Three's Company

Three's Company (1977-84) premiered at the height of the disco era, when sex was on everyone's mind,  so of course it was about people having sex.  Or, rather, about people thinking that other people were having sex:

Janet eavesdrops on Jack, the cooking student, talking to a girl in the kitchen.  "Ok, take it out, slowly...that's it...careful...work your hands more..." 

They're having sex right on the kitchen table!  Disgusting!  Outraged, Janet bursts through the door, to find Jack and his classmate...cooking.

No one actually had sex at any time during the eight year run, not even long-married apartment complex managers, Mr. and Mrs. Roper: joke after joke branded him impotent.  Nor, when they left, self-designated ladies' man Ralph Furley (Don Knotts of The Andy Griffith Show).

Certainly not the two single girls who occupied the apartment near the beach in Santa Monica: plain-jane Janet (Joyce DeWitt, right, next-door neighbor to one of my friends in West Hollywood) and dumb-blond Chrissy (Suzanne Somers, left, who was eventually replaced by two other blondes).

Or their roommate, Jack Tripper (John Ritter, who would later star on Eight Simple Rules with Martin Spanjers).

Wait -- a guy with two girls?  Mr. Roper/Mr. Furley is horrified.  This is the 1970s -- it's impossible for a man and a woman to be alone together without sex happening.  Jack can't live here!

Jack hits on a novel solution: he'll pretend to be gay!  Whenever Mr. Roper or Mr. Furley are around, he'll sashay about, limp-wristed and lisping, and maybe bat his eyes at them.   He'll have to hide his girlfriends, of course, or explain them as drag queens.

What could possibly go wrong?

Not much.  Most episodes ignored the pretending-to-be-gay angle in favor of "thinking someone is having sex" gags and heartwarming sitcom antics:
The roommates get a new puppy.
They buy Mr. Roper's car.
Jack and Chrissy take over Janet's babysitting job.
Janet has two concert tickets, and can only invite one of the roommates.

Jack's gay persona was a negative stereotype, no gay characters ever appeared, and at the end of the series, when Jack plans to get married to a woman, he explains to the landlord that he's been "cured."  The writers had apparently never met a real gay person.  But still, there was a lot for gay kids to like on Three's Company.

1. In the fall of 1977, Anita Bryant's Save Our Children campaign was in full force and our preacher had just discovered gay people, so all I heard about gay people was: subhuman monsters, bogeymen who lived only to seduce and destroy.  It was remarkable that anyone would pretend to be such a being, for any reason.

2. Or that a landlord would rent such a being an apartment.

3. Or that others would willingly flirt with the guilt by association. Even horndog neighbor Larry (Richard Kline) had no qualms about people thinking that he wa friends with a gay guy.

4. Jack eventually forgot to do the limp-wristed bit, becoming a conventionally masculine pseudo-gay guy.

5. You could hear the word "gay" frequently.

6. There were frequent muscular men as guest stars, such as Steve Sandor

In 2012, Three's Company was rebooted in the stage play 3C, starring Jake Silbermann.