I'm partial to the G305, G603, and G602 (depending on what shape you want). They actually have long battery life which means you can use them with standard rechargeable batteries and don't need either a charging mat, or have to plug them every other day.
G602 doesn't last as long as the others, but it lasts at least two weeks with two AA rechargeables. G305 and G603 last literally months. They are good mice in terms of function, too, but the best aspect of them is not having to charge very often.