+1 for the Kensington Expert Mouse, I have 3. The quality of the scroll ring is up for debate but the device overall is much better than anything else I've used.
I also miss the Logitech Trackman Wheel optical. It was cheap, light, and worked very well. I still have one for occasional use.
Kensington Slimblade. Scrolls by turning the ball around the Z axis; it sounds strange and error-prone but actually works perfectly. I now keep a spare in a box on a shelf beside my spare Kinesis keyboard.
I also miss the Logitech Trackman Wheel optical. It was cheap, light, and worked very well. I still have one for occasional use.