It's always fun to contemplate "what might have been" if a certain star had been cast in a famous series instead of the actor or actress who eventually landed the part. 

Mickey Rooney originally tested for Archie Bunker in "All In The Family," but turned it down because it was too controversial. Bing Crosby decided that playing "Lt. Columbo" would get in the way of his golf game and it went to the now iconic Peter Falk instead.

And now two former series producers reveal the roles that weren't in the original "Frasier."

Among those you didn't see - but could have - was Frasier himself. The main character was originally offered to John Lithgow, but he said no. Kelsey Grammer ably filled the breach and is still playing the role in its third incarnation.

Cynthia Nixon almost played Daphne, Martin Crane's helper, but it eventually went to Jane Leeves.

And then there was Roz, Frasier's radio producer. They'd already signed an actress to play the role, despite a good audition from Peri Gilpin. But those in charge ended up not quite liking the quirkiness the chosen thespian brought to the character, so they told her they'd changed their minds and went back to Gilpin. It was probably the best thing that could have happened to Lisa Kudrow, who wound up making millions as Phoebe on "Friends."

More behind the scenes info here.