The studio audience. It's a staple of the late night format, providing guaranteed laughs, cheers, and in some self indulgent cases, high fives. But Craig Ferguson broke from the mold last night, doing his entire show sans studio audience.
It's a bit jarring at first, but you have to hand it to him. - it feels more intimate, more laid back. Ferguson also also acknowledged it was a nod to his predecessor Tom Snyder, who went audience free for years.