Logitech VX Revolution - the best mouse ever produced for me. 4 years old now, serviced four times.
It is small, ergonomic (right-hand), with rubber at the sides. Extremely comfortable to hold for 10 hours. It has 5 buttons, 1 slide button with two positions (never used it), steel wheel with side tilt.
Alas, Logitech discontinued its production and had still not released a better mouse! If you find a new one for sale, I'll get it right away!
