I'd steal a money printing machine.
Buy a huge house, fill it with awesome stuff, buy a lot of awesome arcane machines, fly all of my friends to it, chill for a week or 2.
Buy EA, shut down EA.
I'd probably steal a car and take it for a joyride and then light it on fire. Probably a very expensive car driven from an older man who's trying to relive his glory years.
I kinda have three:
1.Panzer kampfwagon 8, Maus: Because fuck you, it's the worlds largest tank.
2. Hadron Collider: Just to say that I have it... I imagine it would fall into disrepair.
3. A small nuclear device: Again, just to say I have it.