Iron Man 2 (2010)
-When Tony goes through his father's case an old Captain America comic book can be seen inside; later he uses Captain America's shield (a prototype) to build a reactor.
-When Tony is watching the old reels of his father and going through his notebooks, one of the sketches is of a tesseract, drawn in the form of a so-called "Schlegel diagram". The Tesseract is a very important item in both Captain America: The First Avenger (2011) and The Avengers (2012).
-News report of The Incredible Hulk (2008)'s campus battle is seen near the end of the film.
-Stark and Fury discuss Stark's membership throughout the film.
-Agent Coulson finds Thor's hammer in a crater in the post-credits scene.
-Iron Man (2008) and sequels - Weaponry and technology.
-The Incredible Hulk (2008) - Mutation and nuclear power.
-Captain America: The First Avenger (2011) and sequels - Experimentation and espionage.
-Thor (2011) and sequels - Mythology and religion.
-Guardians of the Galaxy (2014) - Extraterrestrial life and cosmic beings.
-Ant-Man (2015) - Telepathy and control of animals.
-Doctor Strange (2016) - Magic and witchcraft.
-The Avengers (2012) - Alien Invasion.
-Avengers: Age of Ultron (2015) - Artificial Intelligence.