I've been on a bit of a Frankenstein bender recently, and reviewed 6 of them, including these three classic 'bad movies'.
Frankenstein Unbound (1990)
Roger Corman's directorial return has some clever ideas, but is wasted on an impossibly short run-time.
Lady Frankenstein (1971)
Classic euro-exploitation horror starring Joseph Cotten (!), with all manner of gratuitous nudity and violence.
Flesh for Frankenstein (1973)
Pushing gratuity to the limits with more sex and gore than ever in this darkly comic film.
Full reviews of these, and more at my new
Mondo Esoterica Guide to Frankenstein.