A topic doesn't get more Cyrus than this... But I agree with all the games mentioned above. A couple that spring to mind for me include Grundislav's and Layabouts "Opera" game, up until two weeks ago I would also have included "The Big Sheep" because that had been on the cards for a few years. I could also add a whole bunch of the games that were featured at AdventureX in 2011 because they seemed to have gone on the back burner, Orbital, Automaticity, Roadwerks and many more
currently lost in time...
M Borg and J Dekker were working on a game called The Visitor but I hear it got abandoned, it was looking awesome. I can't find the images for it but they, and many other "where the heck are they" projects are in threads like this
. That said I can totally understand development taking years on particular games, even decades when you take into account lifestyles and work commitments.
Finally I'd add "Any game by Gravity" because he's been telling me he'll get round to it since 2000
About the same time as Rich's "By The Sword" was announced... But I think I saw Grav's name on some other projects in the works at the moment which is good. At least if some of the projects have been abandoned its good to know the talented from yesteryear still have a keen interest and help out.