Good lord, there are a lot of replies to this thread. Oh well, one more couldn't hurt.
Hmm...tough call, though. The first game for computer that I remember playing and enjoying was Ghostbusters, followed closely by Oregon Trail. However, I didn't really get into a game until Wolfenstein 3D.
The first game I bought on my own was Quest for Excalibur, and the first game that I bought and actually enjoyed was Quest for Glory 1 (the VGA remake, although I did play a few of the text-based Space Quests before that).
Hell, I still enjoy Quest for Glory nowadays, if I can actually get it to run.
And yes, Civilization owned everyone's soul.