I was on Digg tonight, and I saw a link about some more old DOS games and Llayable Demos. Because this was so well recieved last time, I thought I might revive this thread.

DOS Games Archive has 234 gmaes available.
Abandonia has a whole bunch of DOS games and other abandonware.

Obviously there's going to be some overlap with lists this long, but I think there's a fair amount of stuff that wasn't covered before. Enjoy.