The first one is Italian writer/director Umberto Lenzi. Not exactly a household name, and even I have to admit I wasn't previously aware of most of his body of work. But thanks to Rarelust.com, I'm slowly discovering that this man has a definite GIMP tilt to a whole lot of his films, and since he wrote them as well as directed them, it's obvious that he gravitated toward treating women very, very badly in his movies.
I still haven't even seen a majority of his filmography, so this list will be incomplete, but here's a little sample of what I've found so far.
ALMOST HUMAN
A woman is threatened with a knife, then two more of them are hung topless to an overhead lamp before being shot to death.


OASIS OF FEAR
A woman is tied to a chair and a man threatens to burn her tit with a lit cigarette


THE TOUGH ONES
A woman is tied up inside a car about to be crushed in a wrecking yard. There's also a lovely rape scene and several moments of women getting slapped and beaten

HITCHER IN THE DARK
Josie Bisset is drugged, stripped, bound and gagged and made to watch while the killer tortures her boyfriend

NIGHTMARE BEACH
Three different women get electrocuted and a fourth one gets bound and flame broiled by a large incinerator

PARANOIA
Carroll Baker beaten with a belt, tied to a bed and gagged

EATEN ALIVE
A woman bound and gagged and forced to watch another woman get her tit cut off


COP TARGET
Haven't seen this one yet, but here's a still from the Rarelust site

MAKE THEM DIE SLOWLY
Probably his most well-known film, featuring the infamous scene of a woman hung up by her tits

I repeat, I've only seen a small percentage of his movies. The guy made over 60 films! But just based on these, I'd say Lenzi is definitely Hall of Fame worthy.