Was in a bar, drunk. Saw sub-zero rip a head off with spine attached (MK1). Hooked! People would line up and put their quarters on the glass for their turn. If you were any good, you got to play a lot of MK for very little money.
The fighting game concept wasn't new. Street Fighter II was already out and really changed the experience of games for me. No longer was it you vs. the game but you vs. the guy next to you. A real test, not the memorization of patterned programming. Add the ability to knock their head off their shoulders and the satisfaction significantly increased, not to mention the shit-talking.
The other draw was to find the right button combinations to execute the fatalities. These things weren't printed on the side of the cabinet. You had to either figure it out, mostly accidental, or go out or go searching in game magazines and bulletin board systems. The amount of disinformation was staggering and the internet was very young. Then it got weird...easter eggs!
If there was ever a game that sucked your soul inside it, forever trapping you in a digital purgatory, it was the original Mortal Kombat.