The Loved One
Not of This Earth (the original 1957 version, not the softcore 1988 version or the not-as-much-fun 1995 version)
Also on my list was the Ernie Kovacs collection, but that one's now available.
I've got all of 'em on VHS (except Wild Palms), but they all richly deserve a new life on DVD. I mean come on, when we're living in a world where animated torture like Ralph Bakshi's American Pop and Lord of the Rings can be allowed to pollute the surface of a DVD, we can certainly get some of these obscure classics on a disk, can't we?