1. Grrrrr! I had to spend like $2 on Duke Nukem 3D!!!! :P
I bought it in spring when that had it on sale. Lots of memories there, played this a lot when I was a kid (using god mode though, before Half-Life I couldn't really be arsed to play FPSs seriously, they seemed to acrady to me).
The only problem I have is that I have trouble getting used to the old style control scheme; The implementation of mouse look isn't always spot on and Duke moves very fast, which often makes me run into things or fall off ledges.