One of the best multi-reference Easter Eggs came with Age Of Ultron - a film that Josh Whedon had consciously attempted to not double-stuff with too many superfluous mythology gags for the sake of it. When Tony is weighing up who to replace JARVIS with when he needs a new Operating System for the Iron Man tech, he chooses Friday (a reference to the in-comics AI secretary he built for himself), but more notable were the ones he ignored. He also had back-up AIs called Jocasta (a robot built by Ultron as his wife) and Tadashi (the big brother of lead character Hiro from Big Hero 6 who created Baymax), tying into Marvel's animated property.
