E Three. Also known as E Three: The Extra Testicle.
That reminds me of one I saw: “Urine and Feces Family Robinson.” Well, the title. Didn’t actually see the movie.
It used to be a toss-up between Buttman and Throbbin’, and a pregnancy-porn thing we used to sell at the magazine chain I used to work at: Ready to Drop One (and the sequel Ready to Drop 2).
Now it might be Edward Penishands, after having read this thread.
The title of Big Guns, a gay porn, will always be funny to me, because I had a very closeted friend, who we’ll call J, who refused to admit he was anything but straight. One time, while hanging out at the house of a friend named Roy (after J said goodbye to his boyfriend), J kept fast-forwarding and rewinding through the Roy’s movie Big Guns, stopping at every sex scene.
Roy, in the kitchen, kept hearing gasping and moaning. After an hour of this, he went back to the living room, and asked, “J? what are you doing?”
And J said, “Looking for the guns in the title.”
Anyway, it’s not a film, but can the magazine Monster Tits get an honourable mention? That cracked me up every time I saw it. I imagined that big monster who always chased Bugs Bunny, wearing a bikini.
Wasn’t it “Buttman and Throbbin”? I knew a guy in college with a copy of that, and a movie named “Anus the Menace”.
Years ago up in Canada, the police (the RCMP in red uniforms in my mind’s eye) raided a hotel for prostitution. They also seized a mess of pornographic movies (in beta format I bet). One was the Disney movie The Black Hole.
I guess they had to return that one.
I’ve also heard of “Dickman and Throbbin’”, I’m sure there’s multiple movies making similar spoofs.
Both probably exist-I got it from a site about porn spoof titles.
“Anus the Menace” was on that list too.
My friend, upon Googling her name, found that a very prolific porn star had used her (not very uncommon) name for a stage name for a while, producing among other things the masterpiece Four Whores and Seven Years Ago, which still makes me laugh to think about it.
I tried to get it for her for Christmas that year but failed. 
Too funny. The best part, at the bottom of the page, they have:
The Bare Wench Project
Also a good description of my co-workers.
“White Men Can’t Hump”
“Bubblegum”–the title itself isn’t funny, but the promo line was “What goes in pink and hard, and comes out soft and wet?”
Lord of the G Strings
- White Bun Busters* A take off on Ghostbusters.
“There’s Something Inside Mary”
and my favorite, from an episode of CSI:
“Armagettiton.”
“You mean Armageddon?”
“No. Armagettiton. It’s an adult movie.”
“Ah.”
Malcolm XXX
Gilligan’s Bi-Land
Two for the BBW crowd:
Life in the Fat Lane
Fatliners
And my all time favorite:
Bright Lights, Big Titties
Starring Malcolm Sex, pleasing the ladies by any means necessary? 
One I thought up myself: Callgirls of Cthulhu.
I so want to see that made, Guin. I’m picturing something like that episode of Drawn Together, only with more penetration.
My nomination: an imdb link found via b3ta:
1,001 Ways to Eat My Jizz, Part 3: Biscuits and Gravy Edition
Hey, cool! mangeorge has a special consultant’s credit. 
Is that anything like The Cabinet of Doctor Callgirly?
Or Metrocopulatus?