if you want cheap, I have a 2500dpi OCZ Equalizer laser mouse that I highly recommend, you can pay quite a bit of money for the better ones, the Equalizer is a really good price/performance ratio. For
$19, it's a great mouse:
OCZ Technology | Products | OCZ Peripherals | OCZ Equalizer Laser Gaming Mouse
in terms of shape, it's a little more traditional, but sleeked just right I find, incredibly comfortable, it's got decent weight to it too, just the right weight to not be too heavy or too light