I don't mind bad movies ... not every cinematic work can be a hit. I think one had to have realistic expectations and to judge movies according to their ambition and intention - for example, I recently watched House of Wax and Sin City, and enjoyed them both for what they were; a classic, unoriginal horror remake and a comic-to-screen translation respectively.
"Worst. Movies. Ever", for me, can only be the ones that I literally could not see through to the end. And for me, there are only two that are so insufferable that I would rather chew my own legs off than watch to their conclusion.
The Goonies
Minority Report
Awful, deplorable films.