First: Give my parents a few million.
Second: Pay off my girlfriends student loans and pay all her school bills to finish.
Third: Buy a few cars...first to mind. F430 Scuderia, GT3RSR, 993, 993 GT2, 993 GT2RSR, Quattroporte. I'd buy a Cayenne to tow and a enclosed trailer. I'd buy my girlfriend an older 911 turbo as that's what she wants.
Fourth: Setup a racing season, finish this season, and sign for next. Maybe buy a race car to play with such as a GT3 Cup car and a formula car, maybe a FA or FM. Also a Spec Miata.
Fifth: I'd buy a house, not huge, not flashy, just a simple four bedroom house, but a huge garage/shop out back and lots of land.

I'd sit on the rest and live on a budget, I wouldn't waste money or spend it on stupid things like clothes, watches, etc. I'd still work a regular job and such.