The Rock, Daniel Bryan, Goldberg (yes, really)
Rock has been mentioned several times already, so I won't rehash that.
I'm surprised no one has mentioned Bryan yet. Absolutely unselfish top guy.
My Goldberg pick probably has people scratching their heads, so I'll explain... Despite the streak, he never cared about losing. He lost to Chad Fortune, of all people, before debuting on Nitro. He has lost several times in WWE. Yes, there was hubbub that he "that doesn't work for me, brother"-ed a loss to The Fiend. But you know what? I'm okay with that.