Some of those older "DOS" games are still very popular. Unfortunately, the modern OS types cannot run them properly. I keep an older Pentium III Slot 1/600 running with Win 98 installed. I start in command-prompt mode, and all those golden oldies work great. The older Doom/Doom2, Heretic, Hexen, Duke Nukem', Quake and others. Lots of mods still available for those old games, and some are as good or better than the original skits!
Heretic 2 was a "good old game" that still should work with Windows.. same with Hexen 2. Duke Nukem' Manhattan Project is something to relish, also.. but is a 'sidewinder' (joystick required). Quake 2 was good too, and had two extra "missions" that were good. Then there was Quake Arena, with very fast action! Delta Force Land Warrior and Delta Force Extreme are also worth playing. You do not need a "super computer" to run them!!
F@H.. to solve mankind's maladies.. in our lifetimes!