MK3 and MK Trilogy. Apparently there was also MK2 but only released in Japan...

What about UMK3?

As far as I know, UMK3 only came out on the Saturn, SNES, and Genesis... but hopefully someone else can come along and help out, in case I missed one.

MK 2 (only available for Japan and just a few copies). Poor version.
MK 3
MK Trilogy
MK 4
MK Mythologies: Sub-Zero
MK Special Forces

That's all.

You are doing a great job. Sony bought the rights to be the only 32 bit console version of MK3, so Sega turned around and bought the rights to be the only 32 bit console version of UMK3, and then everyone made MKT, but only PSX made it right.

What was wrong with the Saturn version compared to the PSX version?

I find MK2 on Saturn very good and the next best thing to the arcade, if you don't count the music. Is there something in PSX's that makes it worst than Saturn's?

The gameplay. They removed or changed rules for move disabling and pushback to allow for much easier, larger, more broken combos, and they messed up the gravity in the game as well, also allowing for much easier, larger, more broken combos. Greatest Hits MKT for PSX was the only one that truely reproduced the rules and mechanices of UMK3 for the arcade and it also ends up being the most balanced of them because of that.

Ahh, I see. It's been a while since I've played MKT on my Saturn, or any other system... but thanks for filling me in on that.