This is what I use, the Sharkoon Fireglider.
It's the first mouse I've ever owned that approaches a "proper" gaming mouse, and I love it. The DPI button is handier than I expected it to be, and it's nice to finally have a mouse with more than the standard three buttons too. The supplied software makes the mouse extremely customisable. You can customise the weight too (there's a thing underneath that opens up and allows you to add/remove weights) but that's more a gimmick than anything really.
And it only cost me £25! It's one of the best-value peripherals I've ever bought.