I think it’s fair to say that Captain America: The First Avenger was the worst of the Phase 1 Marvel movies. Unlike Iron Man which snap, crackled and popped with wit, charisma and action, it instead merely regurgitated the typical action movie trope of an incapable man miraculously transformed into a killing machine.
Yet three years later, the tables have turned: Iron Man 3, despite being helmed by genius Shane Black (Predator, Lethal Weapon), was overblown, uninteresting, and is thus far the worst addition to Phase 2. On the other hand, Captain America 2: the Winter Soldier is easily the best.