Microsoft Intellimouse Explorer 2.0 is the way to go if you have larger hands. It's a pretty standard mouse too, so it's cheap and easy to pick up. They run about $40 and even though it's wireless, I only have to change batteries once every 4 months or so. (And I'm a heavy gamer.) It's back heavy with a nice sized palm rest, so it's actually really made for larger hands. Let's put it this way, I can palm a basketball upside down, and this is about the best I've found for comfort. It has a 4-way scroll wheel and 2 programmable side buttons.
Here's a review.