Logitech MX Revolution (Buttons)
New mouse (purchased from Fr3d - he didn't like it :P ) to replace my old G5v1. I'm keeping the G5 for my HTPC, and so far, I like the MX Revolution.
The only issue I have with it is that I miss the middle-click of the mouse wheel which I used often on my old mouse. I've assigned the button below the wheel to do that though, so I'll have to get used to clicking that instead of the wheel itself - Turns out you can - I wasn't looking carefully enough at the config software. :P