Sebastian Stan is making waves with his role in Captain America: Civil War, but he was stealing hearts way before he was Bucky Barnes. He has a pretty solid résumé with appearances on Once Upon a Time and The Martian, but one of his most memorable roles has to be Carter Baizen, the Upper East Side bad boy, from Gossip Girl. If you're looking for a good dose of nostalgia — as well as some delicious eye candy — take a look back at some of his hottest GIFs from the show. You know you love it!