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.
There's a lot of great Western developed games on the PSX. I think on average they did a better job than on the consoles a generation before. The Tomb Raider games are probably the standout series, the first one is one of the best games on the system. Another big series I didn't see mentioned is GTA. Maybe the old games are more associated with PC? I played them on PSX and really enjoyed them despite all the slowdown. Heart of Darkness is a nice platformer I just remembered. Also, V-Rally 2 was a pretty good racing game.