If you weren't full of sh.., I'd say Ferrari anything over a Viper. Some of the Ferraris are simply beautiful. But spending $300,000 on a car if you don't already have everything else in the world is very, very stupid. Go buy your 21 year old ass a nice house. You've got plenty of time for toys later on, and you'll be better able to afford them with a paid for roof over your head.
I'd wait to check out a new Nissan Z, or I'd go with an Acura NSX, because I've always liked those.
EDIT, OK, so you've got a house. Well, go crazy, then! Ferrari!