Dom Irrera is a stand up comedian, and also hosts his own podcast called "Dom Irrera Live from The Laugh Factory."

Sam Harris is a neuroscientist and author of the New York Times bestsellers, The End of Faith, Letter to a Christian Nation, and The Moral Landscape. His latest book "Waking Up: A Guide to Spirituality without Religion" is available now.

Float Lab Technologies specializes in designing and manufacturing high-quality Floatation Chambers. A Float Lab floatation chamber provides a light- and sound-free environment.

Steven Rinella is an outdoorsman, author, and television host. He currently hosts MeatEater on the Sportsman Channel.

Joe is joined by Eddie Bravo and the hosts from "The Fighter & The Kid" podcast, Brendan Schaub & Bryan Callen, to watch the fights on Sept. 20, 2014.

Graham Hancock is an English author and journalist, well known for books such as "Fingerprints Of The Gods" & "Entangled" and also a new fiction book called "War God"

Isaac Haxton is a professional poker player and No-Limit Hold 'Em specialist.

Mike Dolce is a fitness trainer and was named the 2013 MMA Trainer of the Year. Check out his latest book "3 Weeks To Shredded" out now.

Ari Shaffir is a stand-up comedian and also hosts his own podcasts "Ari Shaffir's Skeptic Tank" and "Punch Drunk Sports"

Jim Norton is a stand-up comedian, radio personality, author, and actor.

Jimmy Smith and Ian "Uncle Creepy" McCall join Joe to watch the fight on the evening of June 28, 2014.

Gad Saad is Professor of Marketing & Concordia University Research Chair in Evolutionary Behavioral Sciences and Darwinian Consumption and author of "The Evolutionary Bases of Consumption" and "The Consuming Instinct"

Matt Fulchiron is a stand-up comedian and also hosts his own podcast called "The Full Charge Power Hour"

Michael Stevens created the YouTube channel VSauce, where "mind-blowing facts & The Best of The Internet" is shared. https://www.youtube.com/Vsauce/

Ms. Pat is a stand-up comedienne.