Some of the earliest dos games I played were "Thexder" from some Japanese programmers (they also did "Silpheed" but it wasn't as good), and Prince of Persia which I played on my Tandy 1000 EX and TX, when I got a proper 486 PC I played ROTT, (Rise of the Triad) from Apogee, it ran on the same game engine as did all ID games (maker of Doom) in fact Apogee was being run at that time by Tom Hall, one of the original ID team. He came up with all sorts of great games, such Commander Keen, Hocus Pocus, etc. Of course there was ID software with Doom, but along with Doom came all those other games based on the Doom game engine like Hexen/Heretic and Duke Nukem.
I loved the fact that ID software would release game titles as shareware trough a number of college FTP servers, not only could you download shareware versions of Doom but all sorts of add-ons, mods, WADs, etc. I also loved playing Blizzard titles like Warcraft 1 & 2, then going on the still fairly-new Internet to find user created PUDs. By that time though the DOS era was coming to a close.