The gtr's are impressive, but if you don't talk to them juuust right they implode lol. You can't really go wrong with a z06, you can rag the hell out of it all friggin day and it will beg for more.
do you want a true V8 muscle car? get the GT500, pushing around 600 HP. you want a rice rocket? look at nissan or any other 6cyl. import. Oh that's just IMHO.
SRT8 challenger is pretty sweet as well, and you can never go wrong with a corvette.