This is a neat question. Can anybody name any. This was really popular in the 1960's and 1970's. I know Davy Jones from The Monkees made a guest appearence on The Brady Bunch.

Will And Grace has had Cher, Madonna and Barry Manilow.

Ashanti appeared on Buffy, and luckily died by the end of the episode.

Boy George did an A-Team episode.

Whitney Houston did a Silver Spoons episode right when she was starting to take off.

R.E.M. were on Boston Public a few weeks back.

Cyndi Lauper and Yoko Ono both did Mad About You, Cyndi won an Emmy for it

Sting, Mariah Carey, Gloria Gaynor and Jon Bon Jovi have all done Ally McBeal

Michael Jackson, U2, Sting and others have done voice-work on Simpsons.

Elton John, Ozzy Osbourne, Meat Loaf and others have done voices on South Park.

The Beach Boys on Full House
David Crosby on Roseanne
Fabian on La Verne and Shirley
Frankie Avalon and Annette Funicello on Full House
Chad and Jeremy on The Dick Van Dyke Show

El Debarge and Stacie Q appeared on The Facts of Life :lol:

Here's one of these guest appearances on TV shows:

"Full House"

1. The Beach Boys
2. Frankie Avalon & Annette
3. Little Richard
4. Frankie Valli
5. Tommy Page

"The New Scooby-Doo Movies"

1. Mama Cass Elliot
2. Jerry Reed
3. Davy Jones
4. Sonny & Cher

"The Cosby Show"

1. Stevie Wonder
2. Dizzy Gilespie
3. Sammy Davis Jr.