Captain America gets to be cool. Not only does he ditch the pajama suit from The Avengers, but he gets to do some great action sequences. From rescuing hostages on the boat at the beginning, to fighting Hydra agents in an elevator, and dueling the Winter Soldier in the streets. As far as villains go, The Winter Soldier is threatening and dangerous to Cap on a personal level. They're evenly matched to the point that Cap gets beaten to near death by the end of the movie. Like a lot of the great stand-alone titles this one had ramifications for the universe without being world ending or killing off characters. The Hydra reveal suddenly put our heroes on the run without having to make the plot overly complicated. Steve and Natasha on the run highlighted one of my favorite moments of the Marvel universe, and the superhero genre as a whole. They were just two characters learning to work together, they were Steve and Natasha not Captain America and Black Widow. It opened a window to both their characters to be more than heroes that fought bad guys. I also loved the addition of Sam Wilson to this movie. I immediately latched onto the chemistry of him and Steve from their very first scene together. This movie felt connected to a larger universe while still serving the titular hero's development.