Blood and Lace (1971) is a pretty good example. A lot of people don't know of its existence or assume I'm talking about the Bava flick
Blood & Black Lace
http://www.imdb.com/title/tt0066848/
I've been meaning to put it onto disc for a couple of people for trades. Quite a quirky flick.
A lot of the D' Amato stuff seems to slip under the radar compared to the bigger guns like Argento, Bava and Fulci (perhaps due to it's execution?) . I guess its more for the hardcore cinema crowd than the casual horror fan.