Though I know the entire genre was called Doom clones back in the 90's, it's a bit odd to see Corporation/Cyber-Cop listed as one, since it was released in 1990 well before Doom, Wolfenstein 3-D and even Hovertank 3-D.

I'd probably have Hexen, Strife and Heretic closer to the top of my list, but I generally agree with yours.

@fisk0: Thanks. I'm still working on this list so changes will still occur.

While we're on the topic of games that precede Doom - Ken's Labyrinth was released at the start of 1993, well before Doom's December 10th release.

And Blake Stone was infamously released just a week before Doom, which is a shame because Blake Stone's actually pretty good - it's more of a 'Wolfenstein 3D Clone' anyway.

Also, Normality definitely shouldn't be considered a Doom Clone by any stretch - it's a pure adventure game (just in first-person).
If System Shock counts as a 'Doom Clone', then that would probably be my favourite.

@psykhophear Isn't "Doom clone" something of an obsolete term nowadays? A term used before "FPS" became the norm.

What exactly qualifies something as a "Doom clone" anyway? I would only consider games using the same/similar technology and gameplay to be Doom clones (sprite based enemies, no mouse look, etc.). A game like Saints of Virtue for example.

Pre-dating Doom by two years, Catacomb 3-D