low-req games for older/crappy PCs

my RAM is only 256 so i get like the crappiest games ever...i cant even run need for speed U2 decently... XD

The Command & Conquer series is brilliant and the older ones will run on low specced PCs.

You can always run Doom using the ZDoom port, or Skulltag at the maximum resolutions. Here is a list of some I think you could run.
The Quake Trilogy
Morrowind Possibly
Serious Sam
System Shock 2
Return To Castle Wolfenstein
Kingpin The Life Of Crime
Diablo 1 and 2 (Can't go wrong with those games)
Starcraft
Duke Nukem 3D With a modern source port
MAX PAYNE!!!! XD