These famous stars appeared on the show, in appearance order:

Deon Richmond, Gilbert Gottfried, Jeffrey Osborne, LaWanda Page, Helen Martin, Tamala Jones, Tiny Lister, Coolio, Gregory Alan Williams, Warren G, Beverly Johnson, Lawrence Hilton-Jacobs, Antonio Fargas, Marlon & Shawn Wayans, Ernest Thomas, Reggie Miller, R&B group Immature, Richard Gant, Yo-Yo, Tevin Campbell, Gary Coleman, Dawnn Lewis, Downtown Julie Brown, Da Brat (twice), Dorien Wilson, Usher Raymond, Richard Lawson, Ellen Cleghorne, Billy Blanks, Richard Moll, BernNadette Stanis, Williie Tyler, and Jesse D. Goins.:D

I'm still trying to find the episode with Trina McGee-Davis was in (Angela in Boy Meets World, although she hadn't played her yet at the time ;)).

These famous stars appeared on the show, in appearance order:

Deon Richmond, Gilbert Gottfried, Jeffrey Osborne, LaWanda Page, Helen Martin, Tamala Jones, Tiny Lister, Coolio, Gregory Alan Williams, Warren G, Beverly Johnson, Lawrence Hilton-Jacobs, Antonio Fargas, Marlon & Shawn Wayans, Ernest Thomas, Reggie Miller, R&B group Immature, Richard Gant, Yo-Yo, Tevin Campbell, Gary Coleman, Dawnn Lewis, Downtown Julie Brown, Da Brat (twice), Dorien Wilson, Usher Raymond, Richard Lawson, Ellen Cleghorne, Billy Blanks, Richard Moll, BernNadette Stanis, Williie Tyler, and Jesse D. Goins.:D

Don't forget Tyrese "Baby Boy" Gibson, hampdogg! He guest-starred as Coop in the season four cliffhanger "'Hood Sweet 'Hood (Part 1)"! (Oddly enough, the conclusion of "'Hood Sweet 'Hood" aired one year and thirteen days after part one, in late May of 1999 [due to the WB network abruptly putting "The Parent 'Hood" on hiatus, for undisclosed reasons, in May of 1998].)