The word I've heard more today about Mark Haines than any other is "authentic." He was surely that.
He would probably have bristled at that word, because it sounds a little fancy or highfalutin, a little too Upper East Side for a Jersey guy like Mark. Maybe he would have gone for "real."
Whatever the word, the essence it describes is the same: Haines was always, well, Haines. He was always himself, and unapologetically so. The audience got that about him. So did his guests. It's why they respected and formed a special bond with him.
Someone I respect greatly in this game once told me that "you won't be good on television until you forget you're on television." No one forgot that better than Mark.