jefe323 :
I have win 7 x64 and run fallout 3 perfectly fine...
No matter what OS, people are going to find issues; and like it or not, these issues are mostly the users fault
I've had issues with both Fallout 3 and Oblivion that usually gets fixed with a reboot. I attribute this to the program itself NOT the OS or the user as this problem persisted under XP as well as Vista for me (well, at least with Oblivion).
All my other games work just fine with the exception of the occasional game that uses a 16-bit installer (Blade Runner). In that case, I just run that in a virtualized instance (doesn't take much horse power to run that game) under VmWare which does DirectX/3D acceleration. Same with Diablo. But, those are the only two games I have to this with. All my other games work fine. Those that are DOS based, I used DosBox. All the Ultimas work just fine under Windows 7 64-bit, Duke 3D, etc.
Windows 7 is a vast improvement over Vista out of the box. No having to wait for major SPs to fix it, like Vista.