I know for sure there are threads out there. I would assume that usually people would title them something like "Mighty mouse vs. XXXX" or the like.
What every style of mouse you prefer I would say get a Logitech. I use and MX revolution and a VX nano. The thing is that Logitech makes really good products, and they have good support. One big thing for me is replacement parts. A few months ago mmy keyboard was knocked off the desk and the receiver for the mouse was what made contact with the floor. I went to Logitech's site to see how painful a replacement receiver was going to be...
10 bucks is all.Usually the replacement parts are where they get you, but $10 is more then resonable with looking at $100 to replace the whole mouse and everything with it.
Selection, pricing, and support make Logitech the ONLY company I'll buy mice from. Their keyboards are really nice too.