Plan 9 from Outer Space is considered one of the worst movies ever made which also makes it one of the most talked about films too.

Here's a great story from the Medved's about the film:

After the publication of 1978’s The Fifty Worst Films Of All Time, 393 readers tore out a suggestion page provided in the back of the book and mailed it to authors Harry and Michael Medved to inform them of an egregious oversight: Ed Wood’s Plan 9 From Outer Space.

“People really took us to task for it,” Harry Medved said in an interview conducted for this piece. He was only 15 when he co-wrote the compendium with his brother and co-author Randy Dreyfuss. “We were shocked by the flood of fan mail—or, in this case, hate mail—saying, ‘We agree Robot Monster is one of the worst of all time, but how could you write a book called The Fifty Worst Films Of All Time and not include Plan 9 From Outer Space? What were you thinking?!’” In 1980, the snail-mail equivalent of a comments section was vindicated. The Medved brothers published a second tome, The Golden Turkey Awards. Based on the reader votes, they declared, damned, and exalted Wood’s chump-change science-fiction flick as “The Worst Film Of All Time.” The label stuck

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Who knew that snail mail trolls even existed?

Say what you will, but the movie has persevered and in ways it's pretty fun to watch now. And don't forget that this movie gave us Tim Burton's terrific Ed Wood.