Supergirl was the most surprising addition to the Arrowverse. First of all, it started with no real chance of joining that universe: Supergirl was a CBS show to begin with, and it looked like we were going to have to content ourselves with only the occasional cross-network cameo. Starting with the second season, though, Supergirl moved to CW. Thanks to Flash characters such as Cisco developing ways to cross dimensions, there was now an in-universe explanation for her to regularly join up with characters like Oliver Queen and Barry Allen.

And Supergirl hit its stride immediately. The show has an amazing sense of both heart and humor, and the natural charm of Supergirl herself helps this show to often be the very best programming in the Arrowverse. Other times, though, Supergirl drops the ball so hard that we can only assume the ball was made of Kryptonite. From the highest heights to the lowest lows, there are times that even the biggest Supergirl fans have to admit that it's being as bad as the Arrowverse can get it. You don't need X-ray vision to see it -- keep reading to check out the eight reasons why Supergirl is the Arrowverse’s best show and seven why it’s actually the worst!

15 WHY IT'S THE BEST: SENSE OF HUMOR

Melissa Benoist As Supergirl

One of the consistently best elements about Supergirl is the sense of humor. The show is constantly portraying Supergirl herself grappling with larger than life foes, but we also get to laugh at things like her Millennial struggles and her more comical sidekicks like Winn. This sense of humor manages to consistently outshine other shows in the Arrowverse.

Once upon a time, Flash would have beaten Supergirl in this category. However, as the Scarlet Speedster's seasons have continued, Flash has become much more of a brooding hero, and we have less of a sense of humor than ever before. Meanwhile, Supergirl remains a hero that is consistently punching out evil with an enthusiastic and infectious sense of humor that keeps fans coming back for more!

14 WHY IT'S THE WORST: BAD VILLAINS

Supergirl can't be a winner in every category, and in this case, they drop the ball with villains. For instance, the show began by slavishly following a “monster of the week” formula, and even after growing past that, it doesn't know what to do with good villains. One good example is her evil cousin Astra, who died before she could do anything interesting.

Another wasted opportunity is the charismatic villain Maxwell Lord, who by this point may as well have dropped off the face of the planet. Or the menacing General Lane, who must have gone back to shaking down Superman by this point. Ultimately, Kara's villains are disposable punching bags, and it makes it tough to get invested in the conflicts, whether she's throwing punches and lasers or just engaging in a battle of wits.

13 WHY IT'S THE BEST: DIVERSITY

supergirl's alex danvers and maggie sawyer about to kiss

Another element that puts Supergirl above the other Arrowverse shows is that it does the best job of incorporating varying shades of diversity. This includes racial diversity (for instance, the provocative decision to make James Olsen black) as well as diversity in sexuality (allowing us to see the entire emotional arc of Alex coming out). These touches not only lead to stronger stories, but they arguably incorporate the ideals of both Superman and Supergirl's comic history.

Some fans have balked at the idea of comics and comic media openly embracing various social justice ideas. But the truth is that Supergirl (and her cousin) represent stories of immigration, and how both the characters and our world are stronger because of a willingness to embrace new people and new cultures. By baking that diversity into its supporting characters, the Supergirl creators show they understand just what these characters mean to ALL fans.

12 WHY IT'S THE WORST: WEAK ROMANCES

Over time, the other Arrowverse shows have used their seasons to build steady and believable romantic relationships for the main characters. This includes the “awww”-inducing relationship of Barry Allen and Iris West as well as the cute-but-controversial pairing of Oliver Queen and Felicity Smoke. Compared to these relationships, Supergirl may as well be standing still (or just keeping her heart in an icy Fortress of Solitude).

First, the show pushed her towards James Olsen, though after the show moved to CW, they immediately dropped this relationship. Then, we got an interesting pairing of her and the alien Mon-El...that immediately devolved into the melodrama of her sending him away and him coming back married. It seems like romantic partners for Supergirl are just as disposable in this show as the various villains that she fights!

11 WHY IT'S THE BEST: STRONG CAMEOS

Superman Supergirl

Let's face it: a big part of the Arrowverse fun is the cameos. This includes cameos from other shows (like when Felicity drops by to see Barry on The Flash) as well as famous actor cameos to make fans shout for joy. Surprisingly, Supergirl manages to outshine her Arrowverse brethren in this department.

First of all, we get some amazing DC Comics cameos, chief among them being Superman...and with all due respect to Henry Cavill, this is a Superman that is written much better than his big screen counterpart. But we get great actor cameos, ranging from Supergirl movie actor Helen Slater playing Supergirl's adoptive mother to Lois and Clark veteran Dean Cain playing her adoptive father. Oh, and did we mention that the president is portrayed by Wonder Woman herself, Lynda Carter?

10 WHY IT'S THE WORST: REPETITIVE PLOTS

Supergirl, as both a character and show, pays a price for being the stalwart and inspirational hero. At the end of the day, this show has the most repetitive plots in the Arrowverse. And in a universe where almost every season of The Flash is “Barry fights an evil speedster,” this is really saying something!

The core concept of Supergirl never really changed: she works with the DEO to bag alien bad guys while struggling to succeed in her real job at CatCo. This is the formula for season one, and it looks like it will be the formula all the way through the series. We get surface-level changes for the supporting cast (Martian Manhunter meets his father, Alex gets engaged, and so on), but Kara remains static, and so does the core plot of most of the episodes!

9 WHY IT'S THE BEST: THE SPECIAL EFFECTS

SUPERGIRL'S ABILITIES

When it comes to great effects in the Arrowverse, The Flash had previously thrown a pretty mean gauntlet down. It's tough to deny that the show helps bring Barry's powers to life in a way that many of us never thought could happen on the small screen. And while The Flash clearly blew shows like Arrow out of the water on effects, Supergirl takes it to the next level.

Like her cousin, Supergirl has a fairly extensive power set. And the show has kept up by making everything look tangibly real, ranging from her powerful eye beams to the property damage of her super-strength. Finally, they manage to make Supergirl flying look very natural, which is no easy feat. We're sorry, Flash, but we DO believe a girl can fly!

8 WHY IT'S THE WORST: BAD SIDEKICKS

arrow supergirl guardian

In the Arrowverse, your heroes are only as good as their sidekicks. Characters like Diggle and Felicity help to bring out the humanity in brooding Oliver Queen, for instance, while characters like Cisco and Caitlin form an awesome science support crew. Unfortunately, Supergirl got the short end of the sidekick stick.

The show basically doesn't know what to do with the sidekicks. James Olsen was a love interest right up until he wasn't. Later, he tried to be a vigilante hero, and that plot fizzled. Winn started as a coworker and eventually moved to working at the DEO, but this ironically moved him away from the action of the plot...he may as well be a background character! At the end of the day, this is pretty much the Kara and Alex show, and everyone else is just window dressing.

7 WHY IT'S THE BEST:  FAMILY

supergirl-kara-alex-eliza-danvers

One category that Supergirl wins nearly by default is that of “best family relationships.” The rest of the Arrowverse is overwhelmingly focused on found family, with our heroes bonding with their friends and allies in an effort to escape the betrayal and loss of their real family members. Supergirl, though, is quite different.

We see how Kara relies on her adoptive family: she goes to her mother when she's stressed out, and she confides in her sister in an open and honest way. Comparing this to, say, Ollie's weird and secretive early relationship with his sister, and Supergirl shines through. Ultimately, in a show about an alien's heroic adventures, her reliance on her family is what makes Supergirl the most human of these assorted heroes.

6 WHY IT'S THE WORST: THE WEAKEST CROSSOVERS

Flash Supergirl

While Supergirl has the best cameos, the actual Arrowverse crossovers for this show are the weakest. In some ways, this is to be expected: Supergirl's planet is on another Earth, and so it typically takes special events to lure anyone to her Earth or to bring her into larger events like "Crisis on Earth-X".

For instance, as cute as Barry and Kara are together, the Flash crossover in Supergirl's first season is rather forgettable. And in the first major crossover for the entire Arrowverse (in which they fight The Dominators), her own episode is pretty disposable and barely connected to the main story until the very end. The show ended up having a good episode as part of the "Earth-X" event, but Supergirl has a long way to go to catch up on crossover coolness.

5 WHY IT'S THE BEST: IT'S INSPIRATIONAL

Supergirl

On the big screen, Superman has had a pretty rough time. Man of Steel portrayed him as an alien that many feared on sight, and Batman v. Superman showed us a hero who rarely smiled and never inspired. In some ways, that's the biggest plot hole of Justice League: Batman's repeated insistence that the world needs a hero that we consistently saw the world hate right up until he died.

Supergirl, however, manages to be a consistently inspirational show. Kara never hesitates to put herself in harm's way to save lives, and you can never go too far in an episode without getting a miniature speech about the importance of doing the right thing. Is it a little corny? Sure. But no one can deny that this is a character and a show that wants the audience to make the world a better place.

4 WHY IT'S THE WORST: LACK OF CHARACTER GROWTH

Supergirl: The Last Children of Krypton

There is a very specific price that Supergirl pays for being the most inspiratonal Arrowverse hero: she never gets any character growth! Many other heroes are defined by their evolving character arcs: Oliver Queen transitions from bloodthirsty vigilante to reluctant hero, for example. And Barry Allen has grown in both the abilities he can wield and changing relationships with characters like Iris.

Supergirl, meanwhile, is already Supergirl. She has little to learn in terms of new powers and abilities, and no real character arc -- she is consistently the inspirational hero that characters like Oliver and Barry hope to be, but that means there's nowhere to go for her. Throw in the show's strange reluctance to let her have any kind of stable romantic interest, and Kara becomes the most static character in her own show.

3 WHY IT'S THE BEST: SCALE

One thing that comic fans typically enjoy is the large scale of the heroic adventures. We regularly see characters like Batman and Superman taking on threats to the entire planet. In other Arrowverse shows, this element is typically lacking, with heroes focusing on saving individuals or, at most, the city.

Supergirl, though, never loses the thread of how big everything is supposed to be. We've had multiple seasons where Kara has taken on invading alien armies, for instance. On some occasions, she goes through portals to alien planets like Mars just to affect a rescue mission. All of this is fun for viewers but also highlights the character in the best possible way: there is nothing she cannot do, and nowhere she will not go to save the day.

2 WHY IT'S THE WORST: FORGOTTEN STORYLINES

James Olsen and Kara on Supergirl

Part of the thrill of the Arrowverse (and any ongoing story) is the idea of telling long-term stories, building on the characters and events that have come before and creating something new. We can see this in Arrow with the return of characters like Merlyn and Deathstroke, and in The Flash, where Barry's glimpse of a newspaper from the future fundamentally shapes several of his decisions over time.

Unfortunately, Supergirl wins the dubious award for the most forgotten storylines, some of which we mentioned earlier. It seems we'll never get real follow-up on James Olsen's feelings for Supergirl, and the show has similarly dropped his inexplicable passion for being the masked vigilante named Guardian. One of the Big Bads from season one, Maxwell Lord, dropped off the face of the Earth, and he took all of his long-term, hero-hating plans with him. Maybe Red Kryptonite wiped the writers' minds?

1 WHY IT'S THE BEST: SECRET IDENTITY

Kara Danvers Supergirl

Supergirl's cousin Superman basically invented the secret identity, and other comic heroes have followed suit. Thus, we don't just see the heroic exploits of Green Arrow and The Flash: we also see the struggles and triumphs of Oliver Queen and Barry Allen, the men beneath the mask. In terms of secret identities, though, Supergirl has them all beat.

First, Barry's “secret” identity is barely a secret: he takes the mask off at the drop of a hat. And he's basically a crime fighter in uniform and out, so his “secret” identity is just him being Flash in comfy clothes. For Oliver Queen, the show is constantly throwing new identities at him and seeing what sticks (playboy, businessman, public enemy, mayor, and so on). Kara, however, has a fully fleshed-out identity that includes a distinct job she is proud of, game nights with friends, and regular bonding time with her sister.