Logitech MX518 pwns, I have it, I get so many more kills in Counter-Strike now, you can change sensitivity to whatever you want any time.
Plus, you see those two buttons on the side with the arrows? That's right, web browsing back and forward. And you can change them to do whatever you want, so a total of 8 buttons, six are customizable.
Get it. And use the USB>PS/2 adapter, USB is for the sux with mice.