I personally prefer laptop sized mice using laser/optical while being wired or wireless. So i have the Razer Orochi (on sale at the time for 45).
Before, i was really happy with logitech laptop mice (I use these mice on desktops as well) because of the nice precision i get when going very high sensitivity.
If you're going just to have a mouse, 10-15 dollars corded ones are your best bet. Of you plan on shooters and such or multimedia, be prepared to spend at least 30.