Friends

The original idea for the show was going to focus on four characters with Phoebe and Chandler in supporting roles. In the early stages the creators toyed with the idea of Chandler being gay. They changed their mind when they met Matthew Perry. They did, however, insert many jokes about Chandler having gay mannerisms (not knowing about sports, loving show tunes, etc.).

In the opening credits to Friends: The One After Vegas (1999), all of the names in the opening (actors and crew) were changed to have "Arquette" at the end of them, a gag on Courteney Cox Arquette who had just recently married David Arquette.

Joey's statue of a white dog was originally given to Jennifer Aniston as a good luck present from her best friend when she started acting. She offered to lend it to the show for the episode where Joey became rich and bought a lot of stuff. After that episode, the producers decided to keep it.