First one I ever played was MK1 on the super nintendo, but I was unbelievably young, so I'm not sure if that counts.
If you mean first one I ever played that I can remember, then MK4.
If we're talking about the first Mortal Kombat games we ever played, I'd have to say Mortal Kombat Trilogy for the Nintendo 64. If we're talking about the first game that got us into the fandom, I'll have to go with Mortal Kombat: Deadly Alliance for the Gamecube.
Mortal Kombat 1 on arcade..
Ultimate Mortal Kombat 3 on my first home console Sega Mega Drive 2, i still have that console and UMK3 game. Beautiful memories always live with me..
Mortal Kombat 4 for PC. I was 8 I think and my dad bought it, but he turned off blood. I still enjoyed it damn a lot,
I played it with my dad for hours.