Who is Better than Anderson Silva?

I've watched every single one of this guy's fights, and he is by far the best fighter pound for pound. I know the question comes to mind that if he fought a larger opponent there might be difficulties, but I really don't see him losing to anyone. What really pisses me off, is the fact that not a lot of people like him. He still gets boos after his fights, and he needs to get more respect from fans in my opinion. Any input out there from MMA fans, what is next for this guy? Personally I'd like to see him fight GSP. George St. Pierre is in the welterweight division however he could be the only person that would give him a challenge. Still GSP would be a serious underdog in the fight. Anyway lets see what you guys have to say.