Over the years, Zak, Nick and Aaron have invited many guests to participate in some of their most memorable investigations. People and places include Mötley Crüe's Vince Neil and Bruce Westcott, Frank Sinatra's former pianist at the Riviera Hotel and Casino in Las Vegas, Nevada, The Hollywood Ghost Hunters, consisting of Kane Hodder, R.A. Mihailoff, and Rick McCallum at the Pico House in Los Angeles, California, Liz Nowicki at the Lizzie Borden House in Fall River, Massachusetts, Brendan Schaub at the Peabody-Whitehead Mansion in Denver, Colorado, Chad Lindberg at the Linda Vista Community Hospital in Los Angeles, California, Roy Marshall at the Villisca Axe Murder House in Villisca, Iowa, Christian Day at the Witch House in Salem, Massachusetts, Dakota and Rob Laden, the winners of the Ghost Adventures Crew Mashup Challenge, at the Old Charleston Jail in Charleston, South Carolina, Joe Tasso, Wally Luna, and Christy Silva at Bonnie Springs Ranch in Blue Diamond, Nevada.
