Right this second, I only own MKA and Shaolin Monks, but I've owned Ultimate MK3 on SNES, MK Trilogy on PS1 and N64 at different times. Deadly Alliance, and Deception, and the Midway Arcade Classics that had MK2 and 3 (I never sold that one, I just can't effing find it. Really frustrating.) I never should have sold my copy of Deception for Armageddon. I miss that game.
The rest of 'em I either played the Hell out of at friends' houses, or I rented a ton.