Pir (32 level megawad)
Pir.wad

Author: Parkerinfo team
Not port specific, Doom2 megawad.
It is from 1997, so looks better, than the earlyer.
Sometimes dark.
Well playable!

Project-x (32 level megawad)
Project-x.wad

Author: Cyberdemon
Not port specific, Doom2 megawad.
Average design.
Sometimes dark.
Hard gameplay.

Project Space (20 level megawad)
Psp.wad

Author: Robert Juhl
Not port specific, Doom2 megawad.
Quite ok. design.
Sometimes dark.
Good gameplay.