Metal Arms: Glitch in the System, with the graphics and cover system of Gears of War 3.
A Midnight Club game with the city map size of TDU 1 (preferably of a real city and not a fake one), the drifting physics of Juiced 2, the graphics AND car tuning ability from Forza 4, with the bodykit and interior parts from NFS Underground 1 and 2, and the ability to customize the looks of the driver as well.
I'd buy both of those in a heartbeat. .
What's the purpose in owning a Grenade Launcher? The sheer inability to continue life without it ! ! !