Yokohama YK740 GTX. No mileage loss as far as I can tell, but drastically better handling than the OEM tires (I really hated it when the original tires would squeal and nearly lose traction turning right at a red light at no speed to speak of), and maybe a little improvement in noise. And yes, I'm comparing to when the OEM tires were as new as the car.
If you don't get too much snow, I'd go with the Pilot Sport AS4. If you get a lot of snow, go with the CC2. Consumer Reports actually rates the CC2 winter performance in the middle of pack if it was a dedicated snow tire. You pay the price in loss of range, mpg. I have the CC2 on my Subaru and the highway mileage dropped from 31 mpg to 27 mpg compared to regular all season tires.