I think in a similar PS topic awhile back I mentioned Turnabout, kinda like that 70s-80s(?) wooden labyrinth box you had to maneuver the little metal ball through- but so much better. Great music too- nongamers have told me!
Juggernaut & Echo Night- 2 1st person MYST-type games that didnt get the recognition they deserve. EN: Beyond is the PS2 scifi sequel, fairly decent but a bit slow.
Dracula: Resurrection & Last Sanctuary- 2 more MYST-y games that seem subpar but are worth playing through.
Saltwater Sportfishing if you're into that kinda thing, dumbed-down vers. of Sega Marine Fishing, still worth a look.
Disruptor seconded- can anyone recommend Epidemic? It seems a lot like BRAHMA Force, which I liked...