To me, strategy games, mainly the real time ones. Command and Conquer, Age of Empires, Warcraft, Rise of Nations. Not only that, a large number of games had online multiplayer (which I never played back then because dial up), with every player on their own machine and screen!? HOLY SHIT!!!
Oh, even better than any console for the longest time, a significant number of PC games could be SAVED ANYWHERE AT ANY TIME.
Then there was emulation, where even old '95 computers could easily run the majority of SNES/Mega Drive (Genesis) games and back.