Microsoft Comfort Optical Mouse 3000

Pros: Reasonably smooth
Side (magnify) button can be remapped
Reasonably durable

Cons: The scroll wheel is almost impossible to click straight because of the four way scrolling
The four way scrolling is a complete gimmick and barely works
Low profile leaves your fingers dragging on the desk
Smooth scrolling feels like wading in a bog

Summary: This mouse is as expensive as an entry level gaming mouse for a start, which wouldn't bother me so much if it actually worked. The single most annoying thing about this mouse is the scroll wheel. Middle clicking is the single most frustrating thing, and you will always end up scrolling about half a page before you actually press it. I have had this mouse for two years and it still works fine despite being dropped and having the wires gnawed by cats. The magnify button is absolutely useless in my opinion, as you can just zoom in using the keyboard shortcut, but it can be remapped, making it a reasonably useful extra button. I have used this mouse in excess of five hours, with the only hand problem being that my fingers got sore from dragging on the desk, which is more due to my grip and hand size than anything else. Overall, this mouse is overpriced and is ruined by its terrible addons.