hedwards: I was wondering how he managed to break a mouse, and not just one but enough to say again. I don't think I've ever had a mouse break in all the years I've been using computers.
A roller or something broke on my first mouse. Then I bought a Creative Fatal1ty, which was a great mouse until the very moment when it turned out to be a piece of shit that broke its left click as soon as it got the chance. The warranty meant I got a new one, but that broke down in the same way. I replaced it with a cheap Razer, and eighteen months later, its middle click began funtioning erratically. Now I have a CM Storm Sentinel, which wasn't exactly broken but its firmware required an update on a 32-bit system. It's worked fine since then, but I still keep the Razer in a box in case the Sentinel gives up (my PC is a desktop, so I can't rely on a touchpad in an emergency). Maybe I just suck at these things.
The Logitech MX518 is the most reliable gaming mouse I know: two of my friends bought one when it was launched (late 2005 or so) and neither one has broken yet. You should be able to pick one up for 20€ or so, so it's pretty good value as well. I wouldn't buy one, because it can only do 1800dpi and because it's ugly - however, the G400 is the same shape (great), it can do 3600dpi (which should be plenty enough) and, at least on my local store, it comes with a three-year warranty. If I was in the market for a new mouse, that's very likely the one I'd buy.