It depends what you're doing with it. If you're gaming, I recommend a "gaming" wireless mouse like the G700 or one of Razer's offerings due to the higher polling rate. If you're just doing general productivity work or web browsing, nearly anything will do. Logitech's Performance Mouse MX is very nice.
I did notice a slight bit of lag when gaming with the Performance Mouse MX, though, hence my G700 suggestion.