Just like there are different kinds of great films, there are also different kinds of bad films. But, always at the top of my list are:
Jesus Christ Superstar (that AWFUL Australian version)
Summer of Sam (only movie I ever walked out of the theatre on)
American Beauty (most overrated film of all time with the most overrated actor, Kevin Spacey, in it)
"Fundamentalism means never having to say 'I'm wrong.'"
-- unknown