1. Photopia by Adam Cadre (1998) Average member rating: (563 ratings)
gettera says:
This isn't really a game as much as it is a literary short story. One of the best uses of interactive fiction to tell a story I've ever come across.
2. Galatea by Emily Short (2000) Average member rating: (343 ratings)
gettera says:
Absolutely fabulous, Emily Short's dialogue-based game was the first IF I was exposed to, and as a result I hold every game to impossibly high expectations.
3. Zork, by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling (1979) Average member rating: (31 ratings) gettera says:
There are dozens of iterations of Zork, but this one is my favorite. Any version of Zork is a must-play, just for historical reasons, but it's fun to explore this massive world.
4. Spider and Web by Andrew Plotkin (1998) Average member rating: (314 ratings)
gettera says:
This one is an excellent puzzler, and I have one crucial piece of advice: save often, especially near the end.