I'm a Halo fanboy, and although I'm by no means a fanboy of Twilight I am generally defensive of it, simply because I hate the 'haters' that always pop up whenever something becomes popular. It's not cool to hate something, people, okay? Get over it.
Anyway, before I end up derailing the thread all by myself, as i say, I'm a Halo fanboy. However, I'm not a fanboy in the bad sense. More that I'm simply a huge fan of it. If someone has a differing opinion then that's fine, provied it's an informed one. For example, someone says Halo is bad. That's fine, if they've played the games and have that opinion from their experience. If they say it because someone else doesn't like it, then that's a bad thing. It's the haters, and the fanboys who hate any criticism against the subject of their fanboyism, that really grind on my nerves.
Oh, and I'm sort of becoming a Valve fanboy now too...