MCU: Every Hulk Appearance Ranked Worst To Best

6. Iron Man 3

Just like Tony Stark made a surprise appearance in The Incredible Hulk, Bruce Banner returned the favor to his friend by popping up in the post-credits of Iron Man 3, the film revealing that he was who Tony Stark's narration throughout the story we'd just seen was directed at, though Bruce himself wasn't all that engaged.

It's an incredibly brief appearance, one used for comedic purposes more than anything, but it did serve to highlight how Bruce and Tony had become friends following the events of The Avengers. The fact that Tony, of all people, would be opening up like he did to Bruce said a lot about Tony's trust in his new friend, and set up their dynamic for Avengers: Age of Ultron.

Even further, it highlighted the two actors' chemistry with one another, while also giving Ruffalo the chance to make an appearance - however small it was - outside of Avengers films since a Hulk sequel was off the table, an ultimately welcome cameo that further endeared him to audiences.