I voted Other since I use several computers and can't declare any of them as being primary at this point.
With my laptop, I use a wireless two-button tilt wheel mouse. It's a Logitech V220.
With my Win XP tower PC, I use a Logitech wireless mouse/keyboard combo. The mouse has the two main left/right buttons, a tilt wheel, and has an extra small button which can be programmed for various functions. My only complaint about this mouse is that batteries need to be changed frequently. I recognized a long time ago I need to use rechargeable batteries for it.
On another tower PC (Windows 7), I have a USB (wired)
Microsoft Comfort Optical Mouse 3000, a two-button plus tilt wheel plus a small button on the left side for Magnifier. This is one that Computer Hope Admin <hi, Nathan
> wrote a negative review on some months ago, but I have been generally satisfied with it.
Of course, all three of these mice are optical. I was recently reminded what a nuisance a ball mouse can be to clean inside when I visited a friend to assist with some computer issues. His old ball mouse was not very cooperative when moved over the mouse pad. I opened it and cleaned some lint off the sensor rollers and it worked much better.