Showgirls - the absolute most utter waste of film I've ever had the dubious distinction of being subjected to.
Any movie with Madonna in it - hey, she can't sing, let's see if she can act! Can you say, "massive ego"? Only exception - Dick Tracy
Any movie with Cher in it - she should have been put out to pasture, oh, 30 or 40 years ago. Exception - Witches of Eastwick (Thank you Jack!) and Mask (great story)
Godzilla - the travesty that was the "summer blockbuster" version. All involved with this dessecration should be summarily sacked.
The Captain America movie - it went straight to video, and should have gone straight to the trash. This garbage makes what they did in Godzilla look like a loving tribute. Bah.
Star Trek V - Shatner as director = yeeck Simple equation.
Monty Python and the Holy Grail - what a load of fertilizer - no redeeming qualities at all! OK OK, I was just kidding!
The list could go on and on...