7. What Happens in Budapest, Stays in Budapest:
During the big fight scene at the end of the film, Hawkeye and Scarlett Johansson's Black Widow find themselves fighting back-to-back against an overwhelming number of enemies. Instead of being worried, though, they take this time to reminisce about a previous mission in Budapest, Hungary. Ah, the power of true love.

If you were looking closely, though, you may have noticed that this fight sequence bore a strong resemblance to an earlier scene of Hawkeye and Black Widow fighting back to back. It was only on screen for a few seconds, but if you rewind the movie an hour or so, you'll see a clip playing on a monitor on the SHIELD Helicarrier of the pair duking it out with a legion of unseen assailants. Sure looks like Budapest to us.