As much as I love Maroney, I still think Reggie Bush is the better RB. I will say that Bush had a better surrounding cast, but all things being equal, Bush is the best. Not to say that Maroney won't have a Hall of Fame career (I think and hope he will), but Bush is a generational talent. He truly reminds me of a Gale Syers/Marshall Faulk mix. The Gale Sayers part is his all around talent, runner, receiver, returner, and though his moves are more Faulk-like, he does pull off some Sayers/Barry Sanders type moves. Plus I believe he is fastest of all of the names mentioned.
Maroney is without a doubt, the most talented RB we've ever drafted, now it's up to him to convert that college greatness into pro greatness. I think he will, and I think Bush will also. Bush will have earlier success (unless Maroney becomes a returner also, which he is quite good at), but who knows, maybe it will turn into another Curtis Martin/Marshall Faulk type situation, Faulk looked like the better back earlier in their careers, but Martin has surpassed him, though both are HOF bound.