10) Alien 3
Alien Covenant isn’t a one-off. Hell, it isn’t even the first film in the Alien franchise to be a victim of delayed planning and indecisiveness. Alien 3 went through numerous iterations before it finally came to shooting – Vincent Ward’s ‘wooden planet’ vision, featuring space-monks interpreting the xenomorph as the Devil incarnate, came close to being the filmed final idea – but when shooting did finally begin, no final script was ready.
Director David Fincher, who was brought in at the last minute, oversaw a production wherein $7 million in sets were built then discarded because the script was constantly changing. Ideas were lifted from Vincent Ward’s concept and from David Twohy’s prison planet script, to make a mash-up so jumbled it took a year just to edit some sense into the film. The final cut, however, is still no one’s idea of coherent. Also, Fincher has since disowned it.