I would never be able to choose just one.
I would buy a BMW Z8, a Ferrari 550 Barchetta Pininfarina, a Porsche 911 Turbo, a Jaguar XKR, a Corvette Z06, a Lexus SC430, an Aston Martin V12 Vanquish, an ///M5, a Viper GTS... and oh yeah, a HUGE-ASS GARAGE!