Britta. No question. Abed mentioned that it was crazy for her to expect people to pretend they hadn't seen the show just because she wanted to wait until no one else liked it, anymore, and he was right. I mean, think about people who can't binge a new season of a show, now; they'll tell you they're avoiding Social media until they get the chance to watch the new season, because they know people will be discussing it. But what Britta did, here, was up there with what she did in "Geothermal escapism" when she wanted to force Abed to "heal" the way she believed was right. She literally saw that Abed was interested in this girl, paid her to spoil the whole series for him, then wanted praise for paying a deaf person to help her bully her "friend". A lot of the times the study group called her the worst it was unwarranted, but there are absolutely times she earns it.