Steve Rogers, a rejected military soldier, transforms into Captain America after taking a dose of a "Super-Soldier serum". But being Captain America comes at a price as he attempts to take down a war monger and a terrorist organization.
#22 Iron Man 2 (2010)
With the world now aware of his identity as Iron Man, Tony Stark must contend with both his declining health and a vengeful mad man with ties to his father's legacy.
I confess that I get a bit confused about what happened in Iron Man II and Iron Man III as they were both had kinda vague plots. Though I remember 2 continued the plotline of bad people trying to do bad things with Tony's tech. Despite this Tony/Iron Man remained a fan favorite.