Captain America: The Winter Soldier excites me for one main reason: it's supposed to be a more grounded military/political thriller than the rest of Marvel's films. That's the reason that I'm so excited for Iron Man 3. In addition, Captain America: The First Avenger was my favorite Marvel film so far and I'm really excited to be back in that world, even though I'm disappointed that not much will be set in World War II.
Marvel's Phase 2 currently consists of Iron Man 3, which will hit theaters May 3, Thor: The Dark World (November 8, 2013), Captain America: The Winter Soldier (April 4, 2014), Guardians of the Galaxy (August 1, 2014) and The Avengers 2 (May 1, 2015). All are promising. Here's the first image for The Winter Soldier as well: