What's the best ergonomic mouse?

I really like the Microsoft Trackball Optical Mouse

You navigate utilizing your thumb on the trackball, instead of the normal side-to-side wrist movement. It may be a little bulky, but very ergonomic friendly.

Good Luck!
R

I use the perfit mouse. It’s big and quite ergonomic, and I’ve been happy with it.

I’ve been using it for years and one of the extra thumb-buttons doesn’t work, but I don’t miss it much. I have big hands, and I like how large it is. According to the research I did, that’s important.

It’s not reversible, but that may or may not be a factor depending if that’s a technique you use to reduce RSI.