I recently did some research (with help from the likes of Samir, Chris L, mos, etc.) that surfaced in the first appearance of Rick Spangler (aka "Disco Sucks" Dude). Here it is in full:
Musicians who have appeared on the show:
Marky Ramone
Gene Simmons
Bernie Taupin
Glenn Danzig
Jimmy Crespo
Sister Sheila
Window Pain
Necroczar
Necropsy
Hex Head
Laser Allin (GG + laser beans!)
Laser Anthrax (Rev. Ken Miller programmed this at his church)
Punk (featuring Michael Jackson as “Mike Jackyl”)
Glass Houses (Billy Joel tribute band)
Pink Houses (John Cougar Mellencamp tribute band)
Country superstar Kenny Dupree
Troy Renfro (stage name: MC Troy Roy) released a dated nu-metal single called “Honeybone”
The Wednesday Rockets
The Wednesday Rockets Plus Papa
Crust
Barnacle Blues Band
DJ Clue and Liquid Brooklyn
DJ Goo-Goo
DJ Spooky
Toilet Rock:
The Crapeaters
S-hit Face
Pant Pudding
The Hey Now (Andy from Lake Newbridge’s band)
Lovely Boys
The Bill Bixbies
The Craigs
Ted Jacobs and The Now
Sherbert Falls
The Album
The Sleestaks
Denny Leonard and the Lemmons
September Gurgles
The Zoom
Darren Robbins and the Rockstars
Sugar Pie Four
The Bingles
Failure Time
Witchypoo
! I Love You The Ghost Of Ann B. Davis
The Menthols
Larry Neville and The Fun
Bam Bam
Candy-Coated Sugar Smacks
Rick and The Backers
The Resistance (White Power Pop, like if Nazi propagandist Joseph Goebbels wrote lyrics for The Rubinoos!)
White Reign
Bezerker
Norse Savage
Nordic Avenger
PPPP played in these bands:
The Need
The Hurt
The Yes
The No
The Maybe
A few others:
I Hate You The Ghost Of Anwar Sadat
White Tyger (1988's On the Prowl was their big album; Live in the Jungle + 8 was their last release and sold 37 copies)
Taupin/Tarpley
Barbershop Sweat
Anarchy in the Barbershop
West Hoover Barbershop Sparrows ("Barbershop Lover")
Pout
Jester's Folly
Crackpipe Susie
Bret Haskins's New The Clash
Von Trimble
Von Scharpling
The Medical Marijuana
Behemoth, Jr.
Gas Station Dogs
Mother 13 (one album was called High Dive; a single was “Wired”)
MickNick PickMickNick (with some variants)
Old Skull
I-Ron's Reggae Challenge
Put (released single on Chewtoy Records in 1991)
Mister Piggy (Western Maine group)
Hippystock:
The String Cheese Evidence
Dave Matthews Group
Grateful Death
Hippy Johnny’s Original Hippy Band
Darren’s bands (sometimes w/ Tom):
The Burn
The Consolidated (renamed Hell Toupee)
Newbridge Hardcore Bands:
SOL
MST
DLB
PRC
MAR
IHF
NRDO
ULGXB
ZBVYM
Threat to Society (TTS)
Punktallica (Hammerhead’s second band)