The movie that most recently traumatized me was Dreamcatcher. I would have expected Steven King to commit seppuku on live TV to make it up to us for this one. This "thriller" manages to be both sad as a horror movie and worthless as science fiction. The basis of much of the movie is a so-called scaling error: a hippo-sized alien manages to crawl inside a 150lb man. "One worm destroys the world" is right. This whole film seems to be an ad for colon health.
The Patriot was mediocre, but I really don't see how it could be the worst film of all time. And it wasn't nearly as violent as the actual Revolution.
My personal 'F' list:
-Lethal Tender: "Film Canada" at its very worst. Includes lots of sparking bullets!
-APEX: Co-starring Carry Fisher.
-Samuel L. Jackson as Shaft: More sparking bullets than you can shake a stick at-and precious little else.
-Beastmaster: From the "so bad it's almost good" category.
-Arena: Same as above.
-The Forrest Warrior: Chuck Norris as a bear.
-Starship Troopers: Got the joke. Hated it anyway.
-Matt Walberg in Planet of the Apes: So, how did the horses wind up there, again?
-Iron Eagle: Teens vs. Migs.
-Star Trek: The Motion Picture: aka Star Trek: The Blue Movie, Star Trek: Bald is Sexy, Star Trek: Hubris in a Saucer, or Star Trek: Hey, Isn't that the Dad from Seventh Heaven?
At the risk of inspiring someone to see these acursed patterns of magnetic filings on tape, I must mention the 80s anime films M.D. Geist and M.D. Geist: DEATH FORCE. To quote a character from the series the animation is, uh, "how incredibly gross! Aaaaghbleghglugblat!"