These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hilarious in Hindsight: The Flash Gitz parody animation had one of the sergeants singing along with Metallica's "Creeping Death". Come 2013, the official video game has the line "Die by my hand" used when the marines score a melee kill.