Non gamestop comes with the Doctor
Gamestop comes with the Harlequin
I require that Doctor Jack in the box
Aside from the Jack in the box you get:
two exclusive single-player maps (Aqueduct and Trajan Market), an art book, a "hard copy strategy map" of Rome (read: it's paper!), the game's soundtrack and a disc containing trailers, a making-of video and a preview of the AC: Brotherhood comic.
Would be awesome if just about everyone wasn't finished with the game already.