There's one thing that's gotta be said for Fame though:
If enough people in the world know and love you as an idol or something of the sort, then there's that distinct possibility that you could do no wrong wherever you go.
Money can be quite powerful. Backed by the human mind, which is the most dangerous weapon in the world, Money can do quite a lot.
Gravity could be a major runner up, but as far as most know, it just means up is up and down, down. You can do a lot with gravity, though.
Time is most powerful to me, because it enslaves all. No one is free of it's grasp. Everyone needs "just a lil more" of it, and no one has enough of it. In a way, time can be a mean "drug" can it?