Henry Blodget (lol) has written a bunch of stuff in Slate recently about Jim Cramer.
http://www.slate.com/id/2158497/
In that article there's a link to a website that shows that the stocks that Cramer recommended in 2006 underperformed a bunch of index funds. Their methodology is a bit sketchy, but it's an interesting site nevertheless:
http://madmoneymachine.com/portfolios/portfolios2006