I suggest the Logitech G502, Very nice mouse. If you cannot affor it, go for the Logitech G402, a more value option for the gamer on a budget. The G502 is a great upgrade from the G402 if you can affor the extra $20 i think for the G502. I suggest watching the videos Luke/Linus did on the G402 and G502.
G402 By Luke:
G502 By Linus:
(Note: Linus says the scroll wheel click and it being metal, and somewhat slippery, makes his finger slip off occationally, this is not a problem for me, if you are wondering)