It changes all the time. I'm always trying out the Drag Radials that people praise. For summer performance, I like Bridgestone RE11s (replaced by S007A) & Michelin Pilot Super Sport (no longer available in the right sizes, grr...).
The problem is that every time I check, tire sizes have jumped around and I end up researching new brands. I think 245/45/17s are pretty safe, because they came on so many cars, and 275/40/17s probably are, too. But high end performance tires typically cater to what's coming from the factory, which keeps getting bigger, lower profile, etc...
Sumitomo HTR ZIII tires are pretty good. Looks like there's a closeout on them for $121/tire on tirerack. Not a bad bang for the $.
Mickey Thompson Makes a tire I'd like to try or hear about, the "Street Comp." It is made in both sizes. The 275's are $155/tire. Then there's the ET Street S/S, which is THE drag radial to have, IMO -- currently $225. I like the M&H Race master drag radial too. Don't know which is better, but the race master is what fits on my 17x12" wheels. MT doesn't make one for my wheel.