Mortal Kombat II is the greatest fighting game ever. Period. It set a benchmark for the entire Fighting genre.
Graphics: Graphics were very good at the time because the characters are real people. Environments are awesome and some have fatalities if you pull of a certain move in the right place. Blood and gore is HELLA good.
Sound: This game has created all the awesome sounds we know and love. For example SUPERB, WHOOPSIE and multiple other ones. Music is excellent as well. Game developers still use some of these sound effects in their games today.
Value: This is one of the hardest games, ever. You have to practice, practice, practice to get good at it and once you finally pull off that move the reward is unparalleled. This game can last for decades.