I've done quite a bit of research on summer tires, anticipating I'll need to replace the OE original tires soon. I like to read Tire Rack's reviews. They do thorough evaluations of traction (dry and wet), noise, etc. Also consider price and wear ratings.
I've already decided on Michelin Pilot Super Sport tires when I'm ready to buy. For what it's worth, I also have a friend who races regularly, including Car and Driver One Lap (on road + circuit driving), and he strongly recommended the Michelin PSS which he has run on a BMW M3. Check out the Tire Rack review here:
http://www.tirerack.com/tires/tests/...y.jsp?ttid=174