Something I haven't seen talked about much from Will's coming out speech that deserves a mention is his claim that they'll argue over what movie to rent despite always settling on Holy Grail.
This presumably refers to Monty Python and the Holy Grail, a 1975 spoof of the Arthurian legend. While a common favorite in nerd culture, particularly from the time period, we never really hear of anyone in the Party having a fondness for Monty Python. It sort of stands out when Will could have mentioned, for example, any of the Star Wars movies that we already know they love. Combined with malted milkshakes and getting lost in the woods, things that do seem to fit the Party, it almost feels like we're learning about total strangers, rather than characters we've known for years. But I digress.
Holy Grail was a pretty standard, if particularly funny, spoof. Arthur and the knights stumble through their respective roles in their quests meeting all sorts of kookie characters, including a snooty French castle guard, an extremely determined Black Knight, and an enchanter who doesn't seem quite right in the head. It comes off feeling like a story being made up on the spot by a group of drunk friends (or, perhaps, a nonserious D&D campaign).
What really sets Holy Grail apart, though, is the ending. Relatively early in the movie, a (then) modern-day historian is seen taking part in a documentary, only to be cut down by a passing horseman from the movie. Throughout the movie, the action cuts away to police investigating the death. This culminates at the end where, just as Arthur is about to lay siege to a castle, the police arrive and arrest him, shoving the camera away.
The movie abruptly ends there, with no resolution to the actual plot. I imagine it was quite jarring to audiences at the time, and I remember being thrown off guard the first time I saw it. However, it does make some sense in retrospect considering that they show the police investigating a few times.
I don't know if any of this means anything or if the Duffers are just big Monty Python nerds, but it strikes me as a bit coincidental that season 5 contains references to both Ghosts n Goblins, which has a fake ending, and Holy Grail, which has no ending. It's the sort of thing that is frustrating to realize when given an ending as disappointing as season 5 gave us, as both of those referenced properties have, quite honestly, better endings.
