Settlers II is the one I go back to from time to time (though nowadays I’m playing the “History” version on uPlay). And of course, all those old Lucasfilm/-arts and Sierra games.
Also there was this 3D-ish platformer called Sky Roads I used to play a lot back in the day. But I haven’t played that in ages. I don’t even know who developed it.
Oh, and Wing Commander 3 and 4. Both really good games.