Played By: Leighton Meester and Penn Badgley

Even though they started off as frenemies whose only common ground was their separate relationship with Serena, the two characters developed a friendship amongst themselves as the seasons progressed. By season four, the storyline takes a romantic turn when both Queen B and Lonely Boy find themselves single and the only ones in the city. In his hopeless romantic style, Dan shows up at Blair's apartment on Valentine's Day to suggest they kiss to see if they actually have feelings for one another. They do, and they date—pissing off "Chair" and "Derena" fans everywhere.

And come on, any guy who would date his ex's best friend is just begging to be hated on.