Go to your local staples, office depot, etc. and try out the ones they have on display (My local Staples has the whole MX line-up and the M$ opticals, FI).
The Logitechs are technically the best, but I find the MX series to not fit my hand very well, none of them. An uncomfortable mouse with perfect tracking isn't going to be as good as a comfy one with average tracking.
As far as tracking goes, the Logitech MX310 and 510 are awesome. Silky smooth, even for those with Gamer's Mouse Syndrom (where max sensitivity just isn't quiet enough).
Oh, and get an optical. Games or desktop, optical mice are superior in every single way to ball mice. You will never go back. Even optical trackballs are fantastic--only the big Kensingtons can compete with even the cheap ones.
You'll get Logitech recommendations: believe them.
I now have a used Logitech Corded Optical mouse. The one that wass $14 shipped at Neweggg last I looked. It has survived longer than my last three MS opticals. I have confidence the hgih-end models are just as good.