For some reason I decided this week that I wanted to play one of these games again. I've tried a couple of Linux Doom ports. Legacy looks the best so far, but I have yet to get any sound working. I have a set of game CDs I bought to use with the Amiga that include Doom I and II. I may have to get into it again.
I know games have moved on a lot from Doom and even Half-Life, but my PC does not have a great graphics card, so I'm limited in what I can play. I've not even tried any of the many on-line virtual worlds. I'm not sure I want to commit myself to that sort of thing. I just want to blast things now and again.