When talking about art, terms like "bad" and "good" are pretty subjective, and the criteria for each are often not that dissimilar. In horror, especially, a bad movie can be great. It's difficult to narrow down a huge category like "bad horror" into a list of just a few. It's even more difficult to rank those movies; it's like trying to compare apples and oranges (actually, that's easy, they're both fruit—maybe more like ranking sex versus tacos).
None of these movies could be classified as good, but they're celebrations of other people's bad ideas, earnest in their efforts and fascinating in their failure.
In the interest of avoiding the same movies that always end up on these lists, we haven't included too many (we hope!) really well known ones, standbys like Leprechaun In The Hood, Plan 9 From Outer Space, Black Devil Doll From Hell, or Troll 2 (although Monster Dog was directed by Claudio Fragasso).
1. Bug (Jeannot Szwarc, 1975)
A horror movie about bugs. And about how stupid science is.