Quest for Glory (Sierra)- I'm showing my age here, but the act of installing and playing Quest for Glory I Remake (1991) on the PC is what started my interest in computers, back before home internet of even user interfaces... Before computers mattered. These were awesome games. Their graphics blew away the NES, but my computer lagged like crazy and since I had no sound card, it was all bleeps and bloops.
I've turned this game on again since then to find that, unlike Mario and Mega Man, it hasn't aged well. I'd say its modern equivalent is along the lines of Skyrm. But at the time, it was revolutionary; building a hero, one stat at a time and seeing him come to life.
Quest for Glory games were greatly instrumental in my love for fantasy.
Special Mentions: Q-bert
Special Mentions: Queens of the Stone Age
Let's meet again on a better day than Q, shall we?