I have never seen Die Hard. But because I have a passing familiarity with pop culture, I know some stuff about it (probably):
-it's a Christmas movie
-it's super important that people understand it's a Christmas movie
-Bruce Willis plays the hero, John McClain(?)
-Severus Snape plays the bad guy terrorist, Hanz Gruber(?)
-The hero wears a white wife beater and gets glass in his bare feet
-The bad guy has a beard
-The hero's (ex)wife is somehow involved, possibly as a hostage?
-There's something important about a photo on a desk
-The hero goes sneaking about through ventilation ducts
-"Yippy Kayak Other Buckets*"
My brother and his family are here, and now that our kids are in bed, we're about to find out how much of the above is accurate. Woo!
*(edited to so as not to offend delicate sensibilities)