What do these shows have in common?

I'll go with an obvious answer:

They each had (IMO) not-so-good spin-offs:

Happy Days --> Joanie Loves Chachi

Three's Company --> Three's A Crowd

Okay, youre right, BUT I was thinkin of somethin else think of what years they ened, or what the actors and characters names are

Both shows had The Andy Griffith Show actors.
Ron Howard - Happy Days
Don Knotts - Three's Company

Happy Days started in 1974 as a midseason replacement and ended in 1984
Three's Company started in 1977 as a midseason replacement and ended in 1984.

That's all I got.:lol:

Actually, the first thing that came up in MY mind was that Suzanne, Ron, and Cindy (L&S) were all in American Graffiti.:D

Yes, those are two great answers i was looking for, theres ONE more though look at the actors name and their characters