Sites to find player's stats on

What sites are out there to look up players stats, see how they play?

Are any of them better than the others and if so, why?

I see people talking about the sites but I've never remembered to make a note of any of the site names so haven't gone to look myself.

Official Poker Rankings - Poker Ratings, Poker Results and Statistics covers fulltilt and pokerstars.

Also:

sharkscope

Bluff's pokerdb

Poker Pro Lab's Top Shark