Looks wise: The Viper GTS
Performance wise: C6 Z06
Bang for buck wise: C5 Z06
Comfort wise: M Coupe
IMO, the Viper GTS has one of the hottest looking bodies ever to have not made it onto the cover of Sports Illustrated. It has strong lines and powerful curves and a look that just says "fuck sophistication, I got a mallet.". The C6 ZO6 however has some moves to it, power to back it up, and a light weight so it can dance well. The C5 Z06 can be had as low as $25k, can be modded very easily, and with 405HP isn't exactly a slow car to begin with. So it leaves you a lot of scratch for a blower kit or anything else you want. I doubt an LS6 to LS7 swap would be hard at all. The M coupe comes in with the comfort factor. It's going to be the one that you want to take a longer trip in. It'll offer a real trunk, and possibly a back seat depending on which one you get.