One of the most unexpected cameos for me was the appearance of the Millennium Falcon mid-way through the film, as our heroes are greeted by Han Solo, Chewie, Lando Calrissian and C-3PO, the latter two of whom are voiced by their original actors, Billy Dee Williams and Anthony Daniels. Their contributions may only be a line or two, but they lead to one of the best gags in the movie, as Batman steals the Falcon's hyperdrive, causing the Falcon to stall and be eaten by a creature that somewhat resembles a Sarlacc. Though it would have been easy for these geeky references to feel hamfisted and forced, the film's manic energy helps propel it forward, and these cameos are mostly so brief that they don't slow the film down or detract from the overall story.
Stay at home dad who spends as much time teaching his kids the merits of Martin Scorsese as possible (against the missus' wishes).
General video game, TV and film nut. Occasional sports fan. Full time loon.