Great discussion in here so far. When Sanitarium was first released I remember loving the demo, but I just never bought the game (14-year-old kids have to budget a hell of a lot!).
I found a copy of the updated for XP Sanitarium a few years ago at Office Depot or Office Max and played it through then. I don't have time to replay with you guys but will follow along with the a youtube playthrough I found.
This is one of my favorite games. The story is very much like that in the movie (BIG-TIME SPOILER, only read if you've played before)
Spoiler:Jacob's Ladder.
The writing is really great, the puzzles fit within the story, and the characters are relatable.