Every actor makes a bad movie once in a while, it's unavoidable, though it's often not the actor's fault. A script can be great but not translate onto screen, the director could be bad or studio interference may compromise the film to the point that it ruins it.
Even great actors make bad choices, but sometimes they make such movies that they will likely regret ever being associated with them in the first place (though admitting as much seems to be a stretch). Not everybody has a filmography like John Cazale and even some of the true greats have made catastrophic mis-steps.
Marlon Brando made lots of bad movies, Robert De Niro and Al Pacino have made more bad than good in recent years, and it just goes to show that no actor goes through their entire career unscathed, though it's unavoidable that the bad inevitably attracts more attention that the good.
20. The Ghosts Of Girlfriends Past - Matthew McConaughey
Before the McConaissance, as the now Oscar winner was busy leaning on leading ladies and taking his shirt off, Matthew McConaughey made a career in stinkers. And none of them were as bad as The Ghosts of Girlfriends Past, a dreadful re-doing of A Christmas Carol.
McConaughey recycles his schtick from Dazed And Confused without justification, and managed to make something that tried to be romantic and ended up being off-puttingly nasty when it wasn't flat-out unwatchable.