Ian Somerhalder

played Boone Carlyle [S01] in Lost

Boone Carlyle was a rich young man who was on Flight 815 to rescue his stepsister, Shannon Rutherford, from a brutish boyfriend. Boone eventually realized Shannon and the boyfriend were conning him, but he was easily distracted from this fact after Shannon seduced him. Boone always had a soft spot for his stepsister, and had "rescued" her on several other occasions.

Boone spent a lot of time with John Locke, exploring the island and helping him dig out the hatch. Boone was killed after he and Locke found a Nigerian drug plane - Locke encouraged him to climb up into the plane, which fell off a cliff - and Boone never recovered from his injuries.
played Hamilton Fleming in Young Americans

Hamilton Fleming is the Dean's son and like Jake, he's been hiding his true self from his parents and peers. At Rawley, Hamilton falls for Jake, but after discovering Jake's true self, the two became best friends.
played Damon Salvatore in The Vampire Diaries

Stefan's malevolent vampire brother who is intent on finding Katherine. He soon develops romantic feelings for Elena.

Deep down Damon loves his brother Stefan, but they have a tense relationship and often fight because Katherine was only supposed to turn him (Damon) into a vampire but she ended up turning both of them. He maintains that he truly loved her because Katherine never had to compel him. Damon is known for his funny and sarcastic comments in times of danger, which makes him different from Stefan. In the more recent episodes of Season 1, it's been revealed that he is in love with Elena, but she does not return those feelings. Instead he and Elena form a close friendship which causes insecurities for Stefan, who's afraid of history repeating itself between the two brothers. At the end of the season finale, Damon thinks that he is kissing Elena but it turns out to be Katherine. He is deeply infatuated with Elena