As both a Brony and a Mass Effect fan, my opinion may be just a little biased, but I have to say Anti-Fanboy.
The reason I believe this is that, when dealing with regular fanboys, it easy to avoid them, they crop up in certain discussions, and certain forums. ones that, if you know what to look for, are easy to avoid. Oh you will come across them accidentally from time to time, but if you tell them, "I totally respect that you enjoy [insert object of fanboy's love]," they will usually leave you alone. However, on the opposite side you have the Anti-fanboy, someone who has such a deep loathing of something, that they feel the need to hunt down every discussion they can find about said object, and insult or otherwise try to invalidate someone's enjoyment of it, usually by spouting the same goddamned argument over and over again.
Just take a look at any Mass Effect or Pony thread on any forum, there will always be someone who took the time to click on the thread, knowing full well what it was about, for the sole purpose of trying to insult the people who -dared- to enjoy something they didn't. Because, as we all should know, they are the ultimate authority on what is acceptable to like, right?
In conclusion, I picked Anti-fanboy because they are unavoidable, you can avoid or appease a Fanboy. but the only way to get rid of an Anti-Fanboy is to not like whatever he is hating on, and since -everything- that has something someone likes has an opposite person, the only solution would be to hate everything.
Hmm, got a little ranty, but I stayed on topic, so I'll leave it.