Well I haven't played PC games in quite a while so my choices might be out of date.
Non MMORPG would have to be Diablo. I remember having a really good time with it.
For MMORPG it would be Everquest without a doubt. I started playing EQ when it launched and played for 5 years. I would have continued but joining the Navy made that impossible. I have also played WoW, DDO, EQ2, and Guildwars for a bit.
I really miss the early days of EQ. There was some serious good times racing for Vox and Nagafen. Breaking into fear, hate, and air for the first time was incredible. Ok I better stop with my memories or I just might break out into tears....
