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.