Movie: Snakes on a Plane (2006)
In all fairness, a movie of Snakes on a Plane's caliber doesn't need top-notch special effects—low-budget campiness is one of its charming strengths. But several images in the 2006 flick are too bad to overlook, especially considering that director David R. Ellis' crapfest was a big-deal theatrical release, not some SyFy Channel movie-of-the-week (which it should have been).
The worst moment of all happens inside the airplane's claustrophobic bathroom, where a CGI monstrosity slithers its way out of a toilet. You're basically waiting for Samuel L. Jackson to yell, "Get this motherfuckin' straight-to-video bullshit off my motherfucking plane!"