Santana, Van Halen (w/Hagar), David Lee Roth, Sammy Hagar, Styx, Blondie, Stevie Ray Vaughn (the night he was killed, among other times), Meatloaf, Cowboy Mouth, Buddy Guy, Def Leppard, REO Speedwagon, Kansas, Heart, the Who, John Entwhistle (Who, but solo), Rolling Stones, AC/DC, ZZ Top, Neil Young, Crosby Stills & Nash, Tracy Chapman, Bo Diddley, Buckwheat Zydeco, Scorpions, April Wine, the Knack, Steve Winwood, Ringo Starr, Jimmy Page/Robert Plant, Robert Plant (solo), George Thorougood, Violent Femmes, Bodeans, Tina Turner, Joan Jett & the Blackhearts, Los Lobos, Jimmy Vaughn, Doyle Bramhall, Aerosmith, Guns & Roses, Rod Stewart, Barry Manilow, Green Day, James Brown, Ray Charles, David Bowie (with Peter Frampton on guitar), the Hooters, Shania Twain, Jim Belushi (singing), Temptations, Todd Rundgren, Joe Walsh, Sam Kinison (comedy & some music), Coasters, Beach Boys, Al Hirt, Moody Blues, Jimmy Buffett, Grateful Dead, Johnny Lang, Eric Clapton, Huey Lewis and the News, Peter Cetera, Fats Domino, Ted Nugent, Cheap Trick, Destiny's Child, Creedence Clearwater Revisited (without the Fogerty's), Tom Petty, INXS, Midnight Oil, Alanis Morissette, Clint Black, Otis Day and the Nights (band from Animal House), Bon Jovi, Skid Row, Three Dog Night, Radiators, Isaac Hayes, and lots more that I can't think of off the top of my head.
Comedians have been Johhny Witherspoon, Gilbert Godfried, Sam Kinison, Rob Schneider, Gabe Kaplan, and others, but I think those are the most famous ones.