OK - This one is definitely in the running. The Buddy Christ (originally from Kevin Smith's Dogma) was pretty cool, and pretty happy wandering around, spreading his message of "It's Alright." What really endeared me to him, though, happened last night, during a 4 hour card playing marathon in the lower level Marriott lobby. And that was the sight of Buddy Christ, crammed into one of the glass elevators facing the lobby, just riding up, and down, and up, and down, for about an hour. It was awesome.
Here's a couple of shots of him, in full regailia.(the one on the left is from last year's Con.)