Most of the same choices for fronts, too, plus several knobbies if you're in the mood to motocross.
The best-reviewed tires seem to be the Pirelli Diablos. They're available for front and rear.
$53 for rear, $49 for front. I only need a rear because it's feathered badly at 4K miles and handles horribly, but I'm tempted to just go ahead and replace them as a set. I don't trust the "Hoops." (Seriously, what a terrible name! They're basically admitting that it's just a rubber ring, and nothing more.)
For some reason my OEM rear tire has a disconcerting tendency to hop sideways slightly under gentle cornering. Just enough to send my heart into my throat. I've had enough of that kind of pie, thanks.