Most sitcoms have a "hangout" where the cast members congregate at. Here are a few that I can think of:

Three's Company - The Regal Beagle
All in the Family - Kelsey's Bar
Saved by the Bell - The Max
George Lopez Show - Thirsty's
Home Improvement - Big Mike's
Beverly Hills 90210 - The Peach Pit

Anyone else can think of more? That's all I can think of.

Happy Days - Arnold's
Andy Griffith - Floyd's Barbershop
Cheers - Cheers
Seinfeld - Monk's Diner
Green Acres - Sam Drucker's General Store
Night Court - The Courthouse Cafeteria
Murphy Brown - Phil's

Friends-The Central Perk
Boy Meets World-Chubbie's

It was only for one season, but Step By Step had a 1950s diner.

Friends - Central Perk

Laverne and Shirley - The Pizza Bowl

That 70's Show - Forman's Basement

The Drew Carey Show - The Warsaw Tavern

Charles in Charge - Sid's Pizza/Yesterday Cafe
California Dreams - Sharkey's
City Guys - The Manhattan Diner
Family Matters - Rachel's Place

M*A*S*H - Rosie's Bar

Family Guy - The Drunken Clam

The Simpson's - Moe's Bar

Melrose Place- Shooters

Friends-The Central Perk
Taxi - Mario's
That 70's Show - Forman's Basement/The Hub
The Simpson's - Moe's Traven
Family Guy - The Drunken Clam
The Big Bang Theory - Leonard's Apartment
King Of The Hill - Outside Hank's House

Alice--Mel's Diner :lol:
I Love Lucy--The Tropicana

What's Happening- Rob's Place

Mama's Family - The Bigger Jigger
Frasier - McGinty's Pub
The Waltons - Ike's General Store
The Jeffersons - Charlie's Bar

Frasier - Cafe Nervosa

Cheers - The Hungry Heifer

The Partridge Family - The Taco Stand

The Facts of Life - Edna's Edibles

The Boar's Nest - Dukes of Hazzard
Nellie's Restaurant - Little House on the Prairie
Remo's - Caroline in the City

Mork and Mindy - The New York Deli

Family Matters:
Leroys- season 1
Rachel's Place- season 2 & 3
Mighty Weenie- season 4 & 5

Stormi's, the sports bar in Hot in Cleveland.