Don't Be Afraid of the Dark (1973)
Very creepy made-for-tv horror flick about a woman being terrorized by evil little gnome-like creatures which dwell in a house she and her husband just inherited, starring Kim Darby and Jim Hutton. Again it's a classic as far as I'm concerned and has a great cast, but there's PLENTY for the Rifftrax boys to poke fun at!
The three reasons for Rifftrax to tackle it:
1 - The creatures, there's LOTS of opportunities to poke fun at their appearance and make up dialog for them.
2 - The elderly handyman who knows far more than he admits to, riff-worthy for the same reasons as above.
3 - The overall scenario, it's hamstrung by the usual overhanging question: Why the **** doesn't she just get out? Visually it's a very creepy movie and well directed.
Aaron Gritsch commented
It doesn't really have to be super bad to be riffed or bad at all. Anything can be riffed and there is lots of ammunition in this one!