7. Hey Bambi
It's a cover-youre-ears-and-youll-miss-it moment when Happy calls one of Stark Industries secretaries Bambi. This one aside is a reference to Bambi Arbogast, who in the comics is Tony Starks long serving secretary; one of many minor references throughout the Marvel Cinematic Universe to their print based origins. What makes this one particularly noteworthy is how it is the preservation of continuity between films. In Iron Man 2, Margy Moore played the character as a secretary to Pepper Potts, making her reference here a solidifying of the world (admittedly a world with two (potentially three if you count Eric Bana) Bruce Banners, two James Rhodes and multiple Captain America shields).