Doom (1993) for me. The newer custom maps and mods too, ofc, but more often than not I’ll spin up episode 1 or 2 just to play through it.
Actually, if I’m really stressed, sometimes I’ll “play” Doom maps in my head - just walking around, trying to remember as much detail as I can. I find it strangely soothing. Damn, I guess Doom is my happy place