11. Hulk (The Avengers)
The Hulk’s first two appearances in the MCU were shrouded in mystery, in that there wasn’t a clear shot of the huge green rage monster in either The Incredible Hulk or The Avengers until halfway through the second act at least.
This certainly built up the suspense for the character, as both times it was technically a new iteration and a new look for Bruce Banner. His first appearance in The Avengers was fine, but it certainly wasn’t as strong as when he turned up later at the beginning of the Battle of New York.
The Avengers were never meant to include the Hulk, but even so, Tony Stark was certain Banner would show up, and show up he did. He wanted to help fight Loki’s invasion in any way he could, and he most definitely had the tools to do it.
As one of the Chitauri Leviathans floated directly towards him, he revealed to Captain America his secret. He didn’t need to get angry to release the beast, he was always angry. At that, there was a finger snap transformation and the Hulk was bringing down the beast that had previously looked so intimidating in the skies above the Big Apple.