I find that having my arm all the way to my elbow on the desk (my desk is in the shape of a J from ikea) helps with wrist pain. I try to have as little pressure on my wrist as possible. And if I'm at a desk where I can't have my elbow supported by the desk, I'll sit in a chair that has arm rest, and try to support my elbow on the arm rest. So with pressure off of my wrist, I find that any mouse works for me, as long as it is not too small (like the small portable ones for laptops). I myself use the Microsoft sidewinder x8. I like it 'cause the side thumb buttons are nice and big, the mouse is aesthetically pleasing, and ergonomic.