Not to complicate this thread, but the quietest tires you'll probably find are the Bridgestone Potenza RE760 Sports.

They have a more rounded tread-to-pavement profile - - - hence, avoid the pavement slap inherent to square-treaded tires like the OEM Conti's. A moderate priced, soft-rubber ultra-high performance summer tire. I run them and they help the Crossfire feel like a much larger, heavier car. - Nice.