The Justice League certainly fended off a load of trouble in its heyday, but some tasks were simply too much for the core team to handle. After repelling a Thanagarian invasion, the original members of the organization decided they desperately needed some extra hands. Thus, "Justice League Unlimited" kicked off.

RELATED: The 15 Best Episodes of Static Shock

The amount of characters in the animated series was vast, with a number being relegated to helping operations in the background or aiding the heroes directly in their skirmishes. Either way, the supporting cast often never got their due for assisting Superman and crew. We at CBR however, would like to take a moment and honor some of the best to fill out the second, third or even fourth string for the super team.

15 SPEEDY

Speedy in Justice League Unlimited

Green Arrow's ex-sidekick (or ex-partner as Roy likes to say), Speedy was a reserve member for the Justice League. He was called upon by the emerald archer to fight off a mutated, super-powered General Eiling. The red garbed vigilante springs into action, wasting no time and all of his arrows in fighting off the monster. He syncs flawlessly with his old mentor, as the two coordinate their shots, and bravely wields his bow against Eiling once his quiver runs out. Unfortunately Speedy gets the living daylights knocked out of him by the creature, leaving Green Arrow to make his stand.

Although his appearance in the show was brief, Speedy did more than enough to show his value as a JLU member. He wasn't shaken in the least by the monster he was tasked with taking out. Even any hard feelings between him and Oliver were put to the side to focus on the task at hand. Speedy sniped, quipped and fought to the best of his ability in answering the call for assistance.

14 ORION

Orion in Justice League Unlimited

Even though he technically debuted on "Justice League," Orion became an official member of the team when the core group decided to expand its membership in "Unlimited." This estranged son of Darkseid had a lot to learn about selflessness and did so largely during an episode called "Flash and Substance." In it, he sees how the speedster handles his rogues with compassion rather than an iron fist. Orion questions Flash's methods in crime-fighting, going as far as to call the hero a "buffoon" in conversation with Batman. He soon comes to the realization though that despite being less than serious a lot of the time, Wally's way of doing things works out.

Orion was a character that had a lot to learn, but utilized his time as an extended League member wisely. He followed directions and wasn't afraid to speak his mind, even if it made him sound like a bit of jerk. Orion was undoubtedly just trying to make up for his father's evils with his role on the team, but surprisingly made a lot of growth as a hero himself.

13 RED TORNADO

Justice League Unlimited Red Tornado

An android superhero, Red Tornado was often seen participating in missions during his membership with the Justice League. He helped track down Wonder Woman when she was transformed into a pig, fought off Lex Luthor when the villain was temporarily inside the Flash's body and went toe-to-toe with Professor Ivo's nigh-unstoppable android called Amazo. When he wasn't in direct combat with baddies, he was providing assistance wherever he could.

Red Tornado was an exemplary member of the extended Justice League because he simply never quit. When up against Amazo, he never faltered and was literally split in half by the rogue robot's heat vision. Despite that, Tornado was either repaired or got a new body and dived right back into the action a few episodes later. Red might not have been the most powerful, but was always on hand to assist without complaint. His sheer tenacity made him a valuable member of the support team.

12 WILDCAT

Wildcat in Justice League Unlimited

Ted Grant joined the Justice League following the events of the aforementioned Thanagarian invasion. He already had a history of training younger superhero recruits with his top-notch fighting abilities, but was assigned fewer missions as time went on. Wildcat eventually turned to an underground metahuman fighting ring to reinvigorate his fighting prowess, but after nearly killing Green Arrow in a brawl, smartly chose to drop the activity for good. Once he overcame this personal crisis of his, Grant was a consistent fighter for the JLU, intent on never letting his ego get in the way of protecting those in need.

While many members of the extended Justice League might have griped about their lack of missions, Ted Grant took it as a personal slight. He was upset at being relegated to the background and wanted so much more out of his duties in the organization. Wildcat might have gone about it in the wrong way, but he was an example of what could happen when too many heroes overshadow each other. More importantly, he came back from his obstacles with renewed vigor, making him an exemplary member of the team.

11 HUNTRESS

Huntress in Justice League Unlimited

Helena Bertinelli technically only worked for the League for a short amount of time, but was a force to be reckoned with. Huntress took on missions faithfully during the early days of her membership, but fell into her revenge-seeking ways hunting down a mobster named Mandragora. After she was kicked out of the organization for violating their charter, she still remained a friend of the Justice League. She assisted Question in his research into Cadmus and helped Black Canary break free of the mind control she was put under by a rogue named Roulette.

Huntress was a more than capable member of the extended Justice League, but couldn't let her lust for revenge go. Even so, she didn't hold her expulsion against the group for long and even functioned as a support unofficially. Black Canary wished to reinstate Huntress' status in the League but Helena declined because she wished to help as a freelancer. She knew that the League stood for something noble, but sometimes they needed outsiders like her to bend the rules in order to get things done.

10 THE ATOM (RAY PALMER)

The Atom in Justice League Unlimited

When the Justice League encountered an alien structure on Earth spewing hoards of nanotech bots, they consulted their leading expert in the field Ray Palmer. The Atom took on the mission investigating the self-replicating robotic enemies, venturing into the core of the invading ship to find its so-called "dark heart." Palmer devises a plan to give the nanotech core a heart attack of sorts, and destroys it. He effectively puts a stop to the hive mind, saving everyone in the process; including most of his League comrades. After that, Palmer assisted where he was needed, often working on repairs for the Watchtower or secondary missions.

The Atom knew his role within the "Unlimited" league and played it very well. He understood that his skills were fairly niche, so he put them to use wherever they fit. Palmer was willing to take on a dangerous mission alone for the benefit of the group, as well as help out his fellow members in tasks. All around, the Atom was a likeable hero with little ego in the series.

9 ZATANNA

Zatanna in Justice League Unlimited

When Wonder Woman had the misfortune of being turned into a pig by a rogue named Circe, Batman turned to Justice League member Zatanna for support. A talented magic wielder, Zatanna uses her abilities and resources to track down the villain. She fought side by side with Batman in an effort to make Circe reverse the spell she cast on Wonder Woman. Once this mission succeeded, Zatanna continued to fight with her comrades outside of her performance schedule. She repelled Apokoliptian soldiers during their invasion attempt with her magic, proving to be a more than capable fighter on the front lines.

Zatanna wasn't your typical superhero, but she knew how to make her abilities count. She transformed groups of Parademons into harmless doves with a flick of her wand, and launched beautifully dangerous pyrotechnic attacks against enemies in the final invasion. Zatanna also had earned the respect of core members Batman and Wonder Woman for her roles in the League; something that's not easily done even among those with core status, let alone form an extended member.

8 VIXEN

Vixen in Justice League Unlimited

There are very few who could come up against Hawkgirl and live to tell the tale, Vixen was one of them. Joining the team after the Thanagarian invasion, Mari dedicated herself to the Justice League's mission and eventually became romantically involved with John Stewart. This of course created more than a few fiery clashes between her and Hawkgirl (Stewart's ex-girlfriend in the series). Vixen however, rose above the pettiness and saved the hero from certain death during a mission. This formed a strong bond of camaraderie between the two, rather than senseless rivalry.

Vixen was not only adept in overcoming her personal challenges, she was also an incredibly tough fighter. She successfully held her own against a number of rogues, including an intense fight with Shadow Thief while defending John. Despite her earlier clashes with Hawkgirl, Mari proved herself a formidable addition to the Justice League's ranks as time went on.

7 BOOSTER GOLD

Booster Gold in Justice League Unlimited

While many other heroes joined the expanded Justice League to participate in a greater good, Booster Gold simply saw it as his shot at glory. In one particular episode dubbed "The Greatest Story Never Told," Gold is tasked with crowd control but ends up entwined in a heroic adventure all his own. Booster tries to stop an unwitting scientist carrying a black hole from destroying everything he crosses, but gets more and more beat down in his efforts. Finally, Gold is able to nullify the threat (and even deliver a baby along the way), but gets admonished by Batman for leaving his post in the first place.

Booster Gold was an extended member that often got bottom-tier duty because of his selfish attitude. The core members hardly trusted him with missions due to his lack of proper motivation, but Gold was able to turn things around. He used his power suit for good and was often seen assisting the Justice League in multiple missions thereafter. All it took was a little taste of what a job being a true hero was like: noble and sometimes thankless.

6 THE QUESTION

The Question in Justice League Unlimited

Vic Sage certainly didn't seem like much when he made a splash in "Justice League Unlimited," but he proved his powers lied more in his intellect. The Question was an investigator at heart and used his faceless appearance to perform incognito missions. He assisted Supergirl in uncovering her evil clone Galatea's existence. Question also attempted to unearth details about the shadowy anti-hero organization called Cadmus. Even though he was captured by the group, Question was able to discover more information about Lex Luthor's link to Cadmus than the Justice League could have ever learned by conventional methods.

The Question had a specific set of deductive skills that earned even Batman's respect, which led to him being assigned to looking into Cadmus. Vic even attempted to kill Lex Luthor if it meant protecting Superman and the rest of the Justice League's noble legacy in the eye of the public. Even without abilities, Question could fight well hand-to-hand and withstand the worst of torture. Not many League members were asked to go through what Vic did, but he did so without so much as flinching.

5 GREEN ARROW

15 Times The Censors Fell Asleep During DC Cartoons

Oliver Queen was somewhat apprehensive about joining the Justice League at first, even as an extended member. He felt that the group would get too swept up in its world-sized missions to pay attention to the "little guy" in need of help on the streets. Green Arrow was eventually convinced to join, and served as a somewhat grounded voice of reason to a lot of the League's adventures. He helped put a stop to nuclear tyrants, mutated monster generals and even took the time to encourage his fellow heroes back on the path of noble justice in dark times.

Green Arrow might have been on the losing side of a number of scraps during his run in the League, but he never lost perspective or heart. He always did what he knew was right, even if it didn't jive with the orders of his superiors all the time. In the face of alien invasions or world-wrecking beings, Oliver stalwartly nocked an arrow and took aim without hesitation.

4 CAPTAIN MARVEL

Captain Marvel in Justice League Unlimited

Billy Batson got a bad case of "never meet your idols" during his extended membership in the Justice League. A huge fan of Superman and the rest of the group's heroes, Billy Batson was in complete awe of being in the company of some of the world's finest. However, he was treated harshly by the core members, as they felt that Captain Marvel wasn't acting as maturely or level-headed as he needed to be. In an attempt to stop Superman from following a false lead, Batson fights the Kryptonian in a very public battle. Superman defeats Captain Marvel, but realizes he's in the wrong and apologizes.

The encounter proved too much for Marvel's shattered ideas about his idolized superheroes and he ends up quitting the team, but he proved to be one of the most poignant members yet. He was a sorely needed reality check for Superman, whom had grown too embroiled in public image and political maneuvering. The Man of Steel had lost perspective and paid for it.Billy's short membership was a lasting lesson for the core members on remembering why they started the League in the first place.

3 BLACK CANARY

Black Canary in Justice League Unlimited

There were few heroes as tough and tenacious as Black Canary in "Justice League Unlimited." Starting out, Dinah followed orders but certainly had her own streak of rebelliousness. Canary dismantled an underground metahuman fight club, fought off Ultimen from invading the Watchtower and encouraged Wildcat back onto the path of a crime-fighter. She even caught the eye of a certain emerald archer, with whom she shared a budding romance on the show.

Canary never backed down from a fight, as was evident with her numerous punch ups with Huntress and many others. She was tough and her cry only furthered her status as a formidable fighter. Dinah also knew the importance of the greater good, which she kept as an anchor when fulfilling difficult missions like protecting the criminal Mandragora as part of a police operation. She wasn't deterred however, from doing what she could to affect those on a smaller scale, as with Wildcat's crisis. Canary fiercely protected her own, which made her an invaluable comrade to have covering your back on the front lines.

2 CAPTAIN ATOM

Captain Atom in Justice League Unlimited

Captain Nathaniel Adams joined the Justice League early on in the "Unlimited" series. A soldier through and through, Captain Atom executed his missions thoroughly, albeit with a stiff personality. During his Justice League stint, Adams fought off Amazo, the replicating robot aliens and used his abilities to contain a nuclear leak within the Watchtower. Captain Atom struggled with his loyalty to the League versus the U.S. military and clashed against Superman on orders from his commanders. Eventually, Adams saw that his rank was being manipulated by Amanda Waller and rejoined the Justice League without any further doubts to his allegiances.

Captain Atom was a great hero on both fronts. His abilities to absorb and channel nuclear energy was unmatched by any of his peers. He felt a stalwart sense of justice and pride in being on the team. Despite his board-like personality, Adams knew the importance of working as a team and having a sense of camaraderie. He managed to earn the respect of not just his fellow second stringers, but the entire team with his actions.

1 SUPERGIRL

Supergirl in Justice League Unlimited

Kara finally got in on the super-team her famous cousin was already on in "Justice League Unlimited." While she assisted in repelling alien invasions or insane villains, Supergirl also discovered that Cadmus had created an evil clone of her named Galatea. The hero clashed with this villain, often outmatched during their fights, but managed to overcome the rogue. Supergirl also traveled to the 31st century and fell in love with a descendant of Brainiac, choosing to live with him happily instead of returning to the team.

Kara arguably had some of the most character growth of a hero during the "Unlimited" run. She learned to go beyond her limitations as a fighter and to work as a team in her many missions. She did a lot of growing up emotionally, learning not to be so stubborn and accept the help of others. Kara was no longer afraid like she was in the beginning, but now welcomed her new future with open arms. Her departure from the team in order to live in the future was her final promotion from a support member, to a hero uniquely all her own.

Which B-lister on the Justice League team is your favorite? Sound off in the comments!