Optical mice are so last year, I know. Regardless, some of the tried-and-true designs, like the Mx518, can still reasonably compete with their laser bretheren.
An optical mouse is an optical mouse, right? Usually, yes, except when that optical mouse is anything like this one. It has all the standards- you know, two buttons, a scroll wheel, a fetchingly phsychadelic case, etc. It has a few features which set it apart from the rest. It's got a few extra buttons on the side for navigating web-sites or accessing weapon slots in video games (for video games is what this mouse was designed around)- but it's main armament is the deceptively simple set of buttons above and below the scroll wheel which adjust the mouse DPI sensitivity. Most expensive mice use their high DPI counts as a selling point-this one can go high, low, and in-between (and just that- there are only three settings, but I've never wonted for another). The only purpose for this is for gamers- for example, in a first-person shooter, you may want the DPI turned up so you can quickly pan around to meet threats, but when you've made it to your vantage point you turn it way down so you can snipe with precision. You'd never know how handy this is until you've actually used it in a game.
The Mx518 is a great choice in mouse if you don't want to shell out for a laser mouse just yet but still want precision and utility on the fly.