8. Pepper Potts - Iron Man 3
Tony Stark would not be the hero we see onscreen today were it not for Pepper Potts.
She helped design Stark Tower, which would swiftly become home to the Avengers; she helped connect Tony with SHIELD through her friendship with Agent Coulson; and she even runs his company while he's off saving/destroying the world with his team of super-friends.
That being said, she's much more of a background player, and her contributions to Tony's heroic endeavours have been slight (in Iron Man, she visually repulses at the prospect of helping him slot his arc reactor back into his chest), and in the finales of the first two Iron Man movies, was only there so Tony could save her.
But by the time Iron Man 3 came around, oh how the tables had turned.
Transformed into a super-soldier by the Extremis virus, Pepper became super-strong, super-resilient and super-confident in her ability to kick ass.
As a helpless Tony lay before a potent, juiced-up Aldrich Killian, Pepper wasted no time in whacking the villain round the head with a pole, saving Tony's life and halting the antagonist dead in his tracks in one fell swoop - literally.
Sadly, Iron Man 3's final scenes informed us that Pepper underwent an operation to remove the Extremis from her system and return her to normal, but on the plus side, the memory of the character surrounded by fire while sporting a pair of glowing, red eyes is one that's hard to forget.