Since this thread is incredibly old, why not start a new and slightly altered one? My candidates:
That Girl: A struggling actress who can afford a well decorated apartment and the latest clothes? Well now it makes sense when you find out about her high priced escort work…
Gidget: Her supposed boyfriend Moondoggie almost never shows up, but she spends all her time with a best friend who “just can’t find a guy”:dubious:
Charlie’s Angels: This wasn’t porn?
WKRP - A radio station switches to Rock & Roll and the new additions to the staff shake things up. Really just a way to get Bailey and Jennifer naked a lot.
Big Bang Theory - Kinda writes itself, doesn’t it?
Leave It To Beaver - 'nuff said.
Make Room For Daddy - ditto
Two and a Half Men, perhaps. Imagine Charlie Harpers’s bedroom (or kitchen, bathroom, sundeck, etc.) uncensored.
Star Trek: After Hours
The A-Team
Diff’rent Strokes
How I Met Your Mother?
Scrolling through the channel guide, tonight’s offerings are:
2 Broke Girls - The girls really earn their money
Mom - MILF TV at it’s finest
Everybody Loves Raymond - And they do mean Everybody
I Spy - Bill Cosby and Robert Culp explore the world of voyeurism
America’s Funniest Home Videos - highlighting the humourous side of amateur porn
And let’s not forget:
Star Trek:TOS - Kirk’s uncensored captain’s log
Firefly - What happens when a hooker hooks up with a ragtag band of misfits (in space!)?
Dollhouse - She can be anything you want her to be (really close to the real show.)
Buffy the Vampire Layer - This is an actual porn title.
Agents Of S.H.I.E.L.D.(Super Hot International Erotic Lesbian Division) - Do you need a diagram?
Angel - We suck, so you don’t have to.
Bewitched and I Dream of Jeannie are perfectly suited.
Oh, this would be a winner. “Guys, I *promise *he’s not hurt. Let’s watch it again!”
**
Gilligan’s Island
My Three Sons
Kim Possible**
Or Walden’s legendary snake. Not to mention seeing just how desperate Alan is to stay in the beach house. 
Night Court: The Fielding Files
Little Women
Laverne and Shirley
Wild Wild West
Some of the porn parody movies really did try, with good casting, make-up and sets. But the WKRP parody was hurt by too few sex scenes that went on too long, and the pairings made little to no sense. Bailey and Les? Jennifer and Herb? Evan Stone did a great job imitating Howard Hesseman’s Johnny Fever, but they really messed up by not having Nina Hartley play Mother Carlson - “Hirsh!”
There are plenty of written porn parodies that could easily be expanded into movies.
Duh…The Facts of Life. An older woman oversees the ‘education’ of several schoolgirls.
Gold, Jerry! Gold!
Mary Tyler Moore.
“Mary, you’ve got spunk.”
“Well, you will in a minute anyway.”
The Dick Van Dyke Show.
The Good Life a.k.a. “Good Neighbors”. Never mind the self-sufficiency, it’s the wife-swapping in Surbiton that’s more interesting, with perky Barbara getting Jerry all hot under the collar in the Leadbetters’ immaculate living-room while earthy Tom unleashes Margo’s inner slut in the potting shed. And that’s before you get on to the guest of the week 
Two Broke Girls – BROKEN for the PLEASURE of MEN!
The Naked City – Just what it says!
I guess that shows like Californication, Mad Men or Game of Thrones could easily become hardcore porn without changing anything in the script or adding new plot points, just adding the, say, “deleted scenes”.