5. Superman's Self-Referential Cameos
The original Superman includes one of the most fan friendly cameos, thanks to the appearance of a couple of Superman veteran actors. In the first act of the movie, we see Clark Kent racing against a train, which carries a young girl, who we find out is a young Lois Lane. Her mother is Noel Neil and her father Kirk Alyn, who played Lois Lane and Superman in the film serials Superman (1948) and Atom Man Vs. Superman (1950) - Neil went on to play Lois in the 1950s TV show. She also had a cameo in Superman Returns as Lex Luthor's elderly wife Gertrude Vanderworth...
There's also a cameo in Superman Returns for Jack Larson, who played Jimmy Olsen in the '50s television series Adventures Of Superman, alongside Neil, as a bartender along with the new generation Jimmy Olsen (Sam Huntington.)