What other specials could they do?
Robot Chicken has done specials for Star Wars and DC. Here are some more they should do?
Marvel
It's only fair since they've done DC.
Star Trek
If they can do Star Wars what's to stop them from doing Star Trek.
Hasbro
They do a lot of Transformers and G.I. Joe sketches (especially G.I. Joe) so why not do a special revolving around them and other Hasbro products e.g. Jem, My Little Pony etc.
Disney
They've been doing a lot of Disney Sketches lately e.g. Toy Story, Disney Princess etc so why not an entire episode.