The show supernatural has now had nods to all 3 BTTF films;
in one episode the main character is sent back in time and asks where he can find a DeLorean.
In another episode (titled back to the future part II) he is sent to 2015
in the above episode which can be seen here; http://www.1channel.ch/tv-11054-Supernatural/season-6-episode-18
the two main characters travel back to 1861. Right when arriving, one of them steps in horse manure (just like marty does). One of the characters is made fun of for his attire that he thought was authentic of the hold west. The main character refers to himself as "Clint Eastwood". The last thing he does before getting returned to the future is have a quick draw. Also when returning to 2011, he receives a package which the post office has held since the 1860's by one of the characters he encounters (who knows he is from 2011) similar to Marty getting the letter from 70 years ago from Doc.