X360: "Forza Motorsport 3" to the point at which I invested in a Fanatec wheel and clubsport pedals for it. Its superb. Love it, and improved my heel-and-toe no end thanks to proper pedals and an H-Pattern shifter - worth every penny when played on a full 5.1 surround system, tunnels have been modelled to perfection!
PC: "Fallout New Vegas" now its been patched via Steam it runs beautifully - whats not to like about roaming radioactive wasteland, laying claim to whatever you can find, while shooting mutants, modifying weapons and basically getting to do a bucket-load of UE without leaving your PC! A thing of joy.
PC: "DCS: Black Shark" A brutally accurate helicopter combat simulator (Ok, I'm a nerd), of one of the coolest soviet gunships. Amazing sound, awesome flight dynamics - comes into a world all its own once you use TrackIR head-tracking to look around just as you would in reality. Proper awesome, pop up over hillsides, unleash firey death, duck back down. Rocks all socks.
PC: "Race On" From racing masters Simbin, this has some of the best physics to be found on the PC racing scene, cool dynamic weather, and a nice mix of car classes. Has excellent opponent AI that you can really dice with, out-brake and pressurise into mistakes - really cool!
You just press the throttle and steer when needed.
They wont work on windows 7 though 
windows 7 doesn`t like the leathal `starforce` copy protection used 