The MCU has many so-called fan-pleasing moments. Scenes where jaws drop and cheers erupt. But after years of following these very different sets of characters, nothing beats the thrill of witnessing the arrival of a fan-favorite hero in a crucial moment. Or the appearance of a long-forgotten character. A last-minute entrance. A much-awaited transformation. These are all just mere seconds of screentime where, really, nothing supposedly exciting happens. All it is is a close up on a character's face while a triumphant song starts playing in the background.

It's hard to explain to a non-Marvel fan how amazing those scenes actually are. But in the meantime, let's reminisce on those awesome moments where our beloved superheroes arrived to the sound of anything from AC/DC to the Avengers theme song blaring in the background.

10 10. Guardians of the Galaxy - Avengers: Infinity War

In a movie as crowded as Infinity War, it's hard to keep track of every single human, alien and robot involved. The first half-hour was brimming with new character meetings, action sequences, and important plot points. Therefore, it's not unusual that audiences were so completely immersed in what they were seeing that a certain group of alien misfits slipped their mind.

As soon as the words "SPACE" appeared on screen and The Spinners' upbeat "Rubberband Man" starting playing, movie theaters were filled with joyous cheers. After all the death and destruction from the beginning, this was a much needed moment to get everyone happy and excited for what was yet to come. It was a perfect introduction to the Guardians of the Galaxy.

9 9. Hulk - The Avengers

"That's my secret Cap." (Close up on Mark Ruffalo's face) "I'm always angry." Puny little Bruce Banner then proceeds to transform into the Incredible Hulk as he destroys a giant robot alien with a single green-tinted punch. Could there be a more incredible (sorry) entrance for the Green Goliath? If that wasn't iconic enough, this moment happens seconds before the MCU's most memorable scene in history.

This is obviously the 360º shot of all six original Avengers standing in a circle as both the Avengers theme and the Hulk's roar punctuate the air. Finally, Earth's Mightiest Heroes were united, and Hulk could now smash all he wanted as an Avenger.

8 8. Peter Parker - Captain America: Civil War

The Avengers are in disarray. Rogers, Wilson, and Barnes have become fugitives and Tony Stark has to capture them before the situation gets any worse. Iron Man announces he has a plan. Alt-J's "Left Hand Free" is heard and the word "QUEENS" fills up the screen. This seems familiar, except this time there's no group of Guardians. It's just our friendly neighborhood Peter Parker.

Although the MCU was already the dominating superhero franchise at the time, the fans' number one wish was seeing Spider-Man join the Avengers universe. Unfortunately, Sony held the rights to the wall-crawler, not Marvel Studios. Spider-Man has always been the most popular Marvel character since his 1960's comic book debut, so when a deal between Marvel and Sony was leaked, anticipation was at an all-time high. Civil War saw Spidey finally swinging into battle amongst Earth's Mightiest Heroes.

7 7. Captain America and the Secret Avengers - Avengers: Infinity War

After the Guardians made their debut in Infinity War, people were beginning why the First Avenger hadn't yet appeared. This was dealt with quickly, though. After Vision and Scarlet Witch are ambushed by Thanos' children, both heroes find themselves trapped in a very sticky situation. In comes a figure, hiding behind a passing train. And out of the shadow steps Captain America's bearded figure.

What then ensues is a tactically masterful fight between Cap, Black Widow, and Falcon as they swiftly deal with the alien minions. Unlike Stark, Banner, and Thor, Steve Rogers had been out of movie theatres since 2016, (except for his hilarious Homecoming cameo), and this was the Avenger people were most excited to see again.

6 6. Thor - Thor: Ragnarok

Ragnarok was a weird movie. It wasn't just hilarious, it was also stupidly ridiculous. But even in a movie like this, there is room for fan-pleasing, awesome moments, as Thor himself proves. Towards the end, when Hela's zombie army is winning their battle against Thor's allies on the Bifrost Bridge, at the same time, Hela has the God of Thunder pinned down.

In a touching dream-like scene between dead father and son, Odin reminds his eldest that he is not the God of Hammers. Thor pulls himself together and, right on cue, Led Zeppelin blasts out of the speakers as he demonstrates his full potential for the first time in MCU history. Needless to say, he ends up sending everyone on the bridge to kingdom come.

5 5. Thanos - Guardians of the Galaxy

It's a bit strange that the MCU's ultimate villain had his first real appearance in a comedy movie, about a bunch of characters nobody had ever heard of. But that's exactly what happened. After becoming familiarized with sisters Gamora and Nebula, and Ronan, who was working for Thanos to retrieve the Power Stone, we were unexpectedly introduced to the Mad Titan himself (and his famous chair).

Even back then, he proved he could be a very menacing villain indeed, managing to make a huge impact with audiences (and with Ronan) in just a few seconds of dialogue. Josh Brolin' voice as he ends his threat with a frighteningly fierce proclamation is chilling. "Return to me emptyhanded and I will bathe the starways in your blood," he says, as Ronan the Accuser visibly wets himself.

4 4. Red Skull - Avengers: Infinity War

Infinity War was full of surprises, but few could anticipate the reappearance of a supposedly dead villain from the 1940s. Soul Stone theories were scattered all over the place before the movie was released, ranging from the common "Wakanda has the Stone" to the absurd "Tony Stark is the Soul Stone". Nobody guessed, however, that it would make its big screen debut on some random planet, guarded by Steve Rogers' World War II foe.

The long-gone Johann Schmidt AKA Red Skull. There were no cheers here, only gasps of extreme confusion. All that's left now is to guess if and where the former Hydra leader could appear in Endgame, and whether he'll face the Captain a second time, 75 years later.

3 3. Hulk - Thor: Ragnarok

This was Marvel's biggest failed opportunity at giving us a potentially amazing surprise. Unfortunately, Bruce Banner's presence in Thor: Ragnarok was all over the marketing campaign. Including the character's entrance scene. To be fair, it would have been hard to not reveal Mark Ruffalo's character, as he was a prominent part of the cast. But imagine this: The movie is nearing the half-way mark. The audience is fully invested in Thor and Loki's story, in Hela's evil plan, and in the constant hilarious moments.

Thor steps into the Grandmaster's arena, ready to fight the creature that has been repeatedly teased before. There has been no reference to any Avengers whatsoever. Nobody's thinking about Banner. And suddenly, out steps the Hulk, roaring in gladiator armor. Audiences would have gone ballistic. Regardless, it still remains an awesome character entrance.

2 2. Iron Man - The Avengers

There couldn't be an MCU character list without including the genius, billionaire, playboy, philanthropist. When The Avengers came out, people finally had the opportunity to watch a series of past stories weave themselves into one single movie. This was before every Marvel movie became some kind of crossover. In 2012, Iron Man's was definitely the most anticipated appearance. His first interaction with another Avenger didn't disappoint.

As Captain America is fighting Loki, and Natasha Romanoff watches by in her quinjet, someone hacks into the aircraft's sound system. AC/DC starts booming and Iron Man flies past, blasting Loki into the ground, and landing gracefully next to Steve Rogers, perfectly in sync with the song. A few seconds later, history is made as both hero address each other for the first time: "Mr. Stark," "Captain".

1 1. Thor, Rocket, and Groot - Avengers: Infinity War

Infinity War makes up nearly half the list, but for good reason. The sheer amount of characters involved guaranteed there'd be a few well-timed hero entrances. This guarantee more than paid off, as many agree it gave us the best character entrance in the MCU. Thor spent the entire movie with Rocket and Groot on a quest to build a new "Thanos-killing" weapon. When the Battle of Wakanda is nearing its end Thanos' army appears to be winning.

But as all hope seems lost, a massive multi-colored beam crashes into the battlefield, and an axe flies out, killing multiple enemies. It makes its way back and Rocket, Groot, and a new and improved Thor reveal themselves, as the Avengers theme blares triumphantly. This felt amazing enough, but his "Bring me Thanos!" followed by a gigantic lighting blast that kills everyone around him were the cherries on top.

NEXT: 10 Best Improv Moments In The MCU