We recently received an email from an interested observer who has written a nice blog post on the top fan adventures, including games that are in production as well as those which are already completed. He asked if we'd agree to link to it, so I felt that a thread in this section of the forum was best. It's well-written, though I'm a little surprised that the Sierra remakes from AGDI and Infamous Adventures didn't make the list. Perhaps he was only including fan sequels as opposed to fan remakes.
http://www.gevoel.net/top-8-fan-made-adventure-games/