Depends on what you value...comfort and convenience, or raw power and in your face?
I've not sat in a C7, but if it's like all other Corvettes (and I can't see why it wouldn't be), it more comfortably fits larger body types. The Viper? Not so much. The Viper also doesn't accomodate fat chicks very well, so if you have a thing for fat chicks, a Viper isn't for you.
If you plan on daily driving, a Vette would also likely be the better choice...it's not that you can't daily drive a Viper, but it might get a bit old after a while.
If I had to do it all over again, I'd still get a Viper. The C7 is the cool new thing, but like all cool new things, they will find themselves on the back burner when the newer, cooler thing comes along (like a ZO6 or ZR1 variant of the C7).