The Princess Bride

You being on this Wiki and not knowing what The Princess Bride is? Inconceivable!

More seriously: The Princess Bride is a book, and later movie, that's basically required reading for most roleplayers, in part because it deconstructs (and reconstructs) a bunch of old hoary storybook tropes.

When combined with Monty Python and the Holy Grail, probably accounts for 90% of the all quotes around the gaming table. Entire sessions have degraded into just quotes from those two movies. TVTropes has turned the entire quote "Hello! My name is Inigo Montoya! You killed my father! Prepare to die!" into various tropes (although "Hello" was more for the sake of making the whole quote bluelinked, every other sentence had been turned into a trope by that point).

Anyway. See also:

• Memes, of which the movie is a fucking fountain.
• Approved literature and Approved movies, of which Princess Bride is one of both.
• Swashbuckler, since two of the main characters are such.