Imo, definitely a question who's the best. He's done amazing incredible things. He does have a weakness though. I don't think anyone will come along with his reflexes and accuracy for a VERY long time. But I think the "best" are the guys like Jones and Gsp... Who are great in every area.
Anderson is amazing. I'm not taking that away from him. I just don't think you can call a guy "the best" who had a record set for the most strikes landed against.
GSP and Jones are a long way behind Silva. They are yet to defeat adversity like Anderson has.