I use one of those office ones with the false-tit shaped wrist rest on, but it's small and has a lip on the edge. This means when I'm trying to hit a moving target in a game I keep hitting this lip and stopping. Which usually means I die
I have a "Manchester City" mousemat which I got free when I bought Championship Manager 2 at Game. I don't support Manchester City, but at least it is sky blue.
As you can tell it is rather old, but it has been just fine all these years. Admittedly I don't use an optical mouse, and occasionally have to scrape it clean of coagulated sweat deritrus and the odd stray plasm of ejaculate, but otherwise no problems.