I'd probably pick the GTR.... but I wouldn't turn down a Z06 if I was offered one!
Here are the results from Road and Track's Ultimate Track test:
1 Lamborghini Gallardo LP560-4
2 Dodge Viper SRT10 ACR
3 Nissan GT-R
4 Porsche 911 GT2
5 Audi R8
6 Chevrolet Corvette Z06
7 Aston Martin DBS
8 BMW M3 Coupe
9 Mitsubishi Lancer Evolution MR
10 Lotus Exige S
http://www.roadandtrack.com/article....rticle_id=6939