I'm just going to leave a PC game list here, so Dan can explore some more during UPF or make it a feature. I am sure he has not played most of these.
Freespace 2
Operation Flashpoint
Vampire: The Masquerade - Bloodlines
No One Lives Forever 1 & 2
Outcast
Secret of Monkey Island
Day of the Tentacle
Planescape: Torment
Baldur's Gate 2
Thief 2
System Shock 2
Deus Ex
Wing Commander 3 & 4
Falcon 4.0
Comanche 4
Quake 2
Yes, it absolutely includes some of my favorite games ever. Still hope Dan will be frustrated by them because comedy gold.
I'd say that a lot of those would be really hard to get much enjoyment out of if you don't have any nostalgia for them. That goes especially for System Shock 2 (which I played quite recently for the first time in about 10 years, and maaaaaaaaaan it's hard to play), No One Lives Forever 1 & 2, Thief 2, the Wing Commander games.
Especially first person games from that era are fucking rough to play now. I loved Deus Ex when it came out, but I have trouble going back to that game because of it even when it's modded.