5. Gremlins 3
The Previous Movie: Gremlins: The New Batch, the financially disappointing though critically successful follow-up to the immensely popular 1984 holiday horror hit Gremlins, continuing the adventures of cute Mogwai Gizmo as he once again has to contend with the darker side of his race.
Why It Was Abandoned: Aside from the fact that Gremlins 2 was a box office dud, this sequel has lingered in development Hell for decades, with Joe Dante generally swearing off involvement these days. Zach Galligan (who played Billy Peltzer in both films) is keen to return for a third film, and there have been suggestions that it would be filmed in 3D (after all, who could resist the title Gremlins 3D?), though it seems that this has been abandoned in favour of a remake (which, no doubt, will shirk puppetry in favour of 100% visual effect-produced Gremlins).