www.tirerack.com has a good buying guide wher eyou can sort out the available tires according to what qualities are most important to you. Price, dry grip, wet grip, noise level, treadwear.
I have Michilen Pilot Sports on the back of mine (very happy with and the newer ones are supposed to be better) and Yokahama A520? on the front. Car came with this setup (used) but I plan to go all Pilot Sport in the future. They are all 235/45/17 Z rated.
I just replaced my shitty Toyo Proxes with Yokohama AVS ES100.
$588 before tax (staggered wheels-sports package on 540), installed with road hazard and lifetime balance. I made some research before buying and was recommended by many, this seems to be quite popular and good price. Originally wanted the Pirellis or Michelins but they are too expensive. So far so good.