get the logitech mx518 or g5. stay away from wireless for gaming. Used the razorback its ok but I do not like the position of the side buttons. they are too easily pressed.
After owning a wireless for many years i didnt think i could go back to wired, however ive just bought a G5 and i dont even notice the cord!
I highly recommend the G5, its the best mouse i've ever used by far!