What a strange phenomenon Three's Company is to look back on. It's very much a product of it's late 70s-early 80s time, with a basic premise almost unthinkable in today's more aware/sensitive climate, the bulk of the show's comedy mined from a straight man pretending to be gay. It's rampant with crude stereotypes, and once you throw in the unapologetic cheesecake depictions of the female co-stars, it's a recipe that would be unlikely to get off the ground today.
And yet it worked then, and even to an extent now, largely because of John Ritter's comedic gifts and the absurdity of the misunderstandings that undergird every episode. Ritter's goofy protagonist was the Navy veteran Jack Tripper, channeling the pratfalls of Dick Van Dyke and exuding a kinetic, anxious charisma as he lies about his sexual orientation to secure lodging with his female roommates. Like John Cleese's Basil Fawlty, Tripper is a bad liar, lacks grace under pressure, and seems predestined to make the worst possible choices at all times. And yet while Tripper has a tincture of sleazy playboy, he's also basically good-hearted and loyal. The show might lack a contemporary social awareness, but there was also a sort of implied gender equality - they all made bad choices, they all made mistakes, and they all managed to forgive each other and did the best they could.
Plus, Jack Tripper was funny.