4. Pepper Potts
I'll admit it: I did not like Pepper Potts when I first saw Iron Man back in 2008. I thought she was bland and had no personality. She seemed to be a glorified personal assistant who did absolutely nothing while Tony Stark got all the personality, charm and wit. I was wrong. If Tony Stark is the apparent golden boy of the MCU, Pepper Potts is the glue holding him together. He would quite literally be nowhere without her and she deserves more praise for keeping him sane whilst also being an important, intelligent, and no-nonsense CEO. How she keeps it together, I'll never know. In the first two Iron Man films, we saw Pepper evolve from Tony's life-saving assistant to efficiently running Stark Industries. Her romantic life with Tony doesn't belittle her achievements. Rather, she has become the rock that Tony depends on. Without her, we'd have no Tony Stark and most likely, no Avengers. She's also incredibly witty and quick on her feet. Remember that suspenseful scene in the first Iron Man where she was downloading secret files right in front of Obadiah Stane and successfully ran off with them? I know I would not have been able to pull that off as calmly as she did. We also recently got to watch Pepper became inherently more kick-ass in Iron Man 3, when she rescued Tony Stark (yet again) while wearing the Iron Man armor and rescue him (seriously, again) and kill the villain at the conclusion of the film with her new Extremis powers. Granted, she was given her Extremis powers as a negative, but hey, she used them to her advantage. Sure, she was shocked by how violent she became and she was afraid of hurting Tony, but ultimately, she was the hero at that moment. And like Tony, I couldn't love her any more.