The prairie dog at the beginning of the Indiana Jones 4 video quotes two Star Wars characters: Jar Jar Binks, and a Jawa.
One of the human explorers in Avatar references another movie James Cameron directed when he exclaims, "Game over, man! Game over!" Selfridge also echoes Ripley's line that they "should nuke the site from orbit. It's the only way to be sure."
Recursively, the crew in Aliens references Avatar when they joke about finding Unobtanium.
Wolverine stealing the show during the musical number in "How Frozen Should Have Ended" shouldn't come as a surprise to viewers who know about Hugh Jackman's past in musical theater.
In the video for Captain America: The Winter Soldier, Steve scoffs at the idea that a major Marvel character will die, likely a reference to the fact that Cap really was shot in the comics. This can be seen as HISHE Tempting Fate as Chris Evans has stated he is planning to retire from acting after he's completed the Captain America trilogy.