I noticed when watching Suicide Squad and Batman v Superman just how many references to other comics there were and how many easter eggs in the film. I rewathed all the old films too and noticed even they have them like there is a sketch signed by Bob Kane in Tim Burton's Batman. Here are some of the good easter eggs http://screenrant.com/secrets-hidden-in-dc-movies/ but what other ones are there? Particularly interested in the older films, like the original Superman. Any from then?