Lots of people, besides Sierra, have created their own game based upon the AGI interpreter. This site plans not on listing all games but on a select few to help people get the right idea of the quality that these people can produce. The aim is not to offend anybody by not listing a game, there are many AGI sites out there that do a very good job of that already. There is an emphasis on completed games, but it is not the only factor in listing games. To show no preference of games, I have made the list in alphabetical order.
Some games are packaged along with a suitable interpreter. If you download a game and cannot find an executable to start the game, try and interpreter from the Downloads section of this site. Try the interpreters in the suggested order.
Operation: Recon by Randy Dykstra, Nat Budin and Leigh Ann Frey
Here are a few sites where you can get more information on other fan made AGI games. They are also handy for other AGI information.