There are seriously way too many to choose from (on newegg). Can someone help me pick? I'll give you a cookie. I've narrowed it down to these two but I'm not sure if there is a right or wrong one. So go ahead and recommend a different one if you see fit.
In a $15 product, you won't find any real technical differences. It's the type of mouse you just run off and buy without thinking. If you need just a mouse, just pick any one that's available. If you need a real fancy pancy gamer mouse that sets you back $100 or more, then start thinking about the technical differences.