I'm more bothered by the Anti-(GIRL)fags. They're more annoying in my opinion. Right now it's the anti-Zinniafags. Before that it was the anti-Courtneyfags, and anti-Flanneryfags. It goes all the way back to the original series.
But if I had to choose one, I guess it'd be Serenafags, but I'm biased since I'm not really a fan of hers.