The unexpected death of everyone's favorite pitchman, Billy Mays, has left his friends in shock.

"I'm in a state of disbelief," Billy's close friend AJ Khubani tells Life & Style. "Billy Mays was a terrific and unique individual, both personally and professionally. He was a wonderful human being and a true family man."

AJ had most recently worked with Billy on Pitchmen, Billy's Discovery Channel show. "He was truly one of a kind," AJ says. "He was a man passionate about his family, the products he so successfully pitched, and the industry that was so dear to his heart. He will be sorely missed."

Billy, 50, died in his sleep at home in Tampa, Fla. this morning. The cause of his death is as yet unknown.

Photo credit: Retna