I recently put a pair of Continental Contisport tires on the front end. I am very impressed. I had to throw 245s on instead of the OEM 255s because that is all that was available at the time. However, even though they are a little narrower, they stick like glue! With the the narrower contact patch, the car doesn't have nearly as many problems with tracking in all the ruts in the roads around here. The ride is better than the stock GSCs as well. I did a little research and unfortunatly they don't produce anything wider than 265s. Meaning, although they can be bought for the front end, you can't get a matching set for the rear

ad . Otherwise when it comes time for my rear tires, that is what I would be jumping on!
FYI, right now I have OEM GSCs on the back, which have been great, but a little too much grip around corners, allowing for the car to plow when pushed hard. I don't like understeer at all. With the Contis up front, not only does the car no longer understeer when pressed, but the front end has about about the same amount of grip! This gave the car a much more neutral balance when being pressed. It doesn't just come unglued all at once. When pushing the car into and around corners, I can feel just when the rear end is wanting to let go. Just as the rear starts to come loose, the front end starts reaching it's grip limits as well. It happens very gradually, so instead of drifting around a corner sideways, you have plenty of time to decide what to do. So far, letting up slightly on the throttle brings the rear end under control and stabilizes the rest of the car...glue the front back down. There is one particular corner that is EXTREMELY sharp near where I live, 15MPH posted caution. Previously my best speed around this corner has been 50MPH with the front end plowing a little bit and all 4 tires yelling at me, however the car stayed completely in my lane. With the Contis up front, 50MPH around this same corner is like a Sunday cruise. No complaints from the car at all, tires are quiet, and the only thing that gives away how fast you're actually going are the g-forces which are attempting to meld you with the door!
Recently we had about 6-8 inches of snow on the ground. I expected such a sticky summer tire to have NO traction in the snow. To my amazement, the Contis stick great in the snow! In short, I'm very impressed, and wish they made a matching set for the Corvette! Just a little more FYI...Continental also produces an even higher performance tire!:J Also not in OEM rear size

Best of all...PRICE!!! I haven't found anything with compatible ratings for nearly the same price (last I checked anyways)
My disclaimer...I don't suggest anyone attempt the manuevers expressed in the preceeding statement, nor do I suggest anyone exceed the posted speed limit. I do not attempt high speed manuevers with passengers in the vehicle. SAFETY FIRST Always wear your seat belt.
I didn't do it, nobody saw me do it, you can't prove a thing!