Personally I'm using a Microsoft Wireless IntelliMouse Explorer 2.0
(Big mouthful of a name), and it works great, absolute wonder to use.
My only complaint though is the lack of physical feedback on the scroll wheel. eg. Logitech mice will allow you to feel a "click" as you scroll, giving you an idea how much you've scrolled. The MS one doesn't.
It's a little pricey at $79.99 (FutureShop price), but it's worth it, but it does have a 5 year warranty on it.