Skulduggery Pleasant/Shout Out

It bears mentioning Derek Landy is a self-professed comic reader, gamer, movie geek, etc. Which is probably why there are so many of these.
 * To Watchmen in the second book.
 * Possibly to The Hitchhiker's Guide to the Galaxy with the tagline of book three- 'Do Panic' on the cover.
 * The Cthulhu Mythos are discussed several times.
 * To The Blair Witch Project in book four.
 * To Hamlet on the Book Four cover.
 * Part of a chapter towards the end of the fifth book seems to be lifted straight out of a certain swordfight scene from The Princess Bride.
 * There is a moment in the fifth book which references the "spanish inquisition" sketch from Monty Python.
 * It was... an ex- rabbit.
 * One of the words used to  was "Mellon".
 * Look out for the Empire Strikes Back reference in Book Five: "Not a scratch, Ghastly"
 * There's a Posthumous Character named Trope in the third book. Coincidence? I think not.
 * Valkyrie is worried about "hulking out" in book six.
 * "Help, Sigourney Weaver! Help!"
 * "Like Jules, in Pulp Fiction?"
 * "We're not Buffy and Angel, OK? We're not Romeo and Juliet. We're not those guys in West Side Story. We're not even Edward and Bella."
 * In book 6, when Carol and Crystal ask Valkyrie to teach them some "tricks", she tells them they're not called tricks, and the twins correct themselves to saying "illusions" instead.
 * mentions flying like Superman.
 * There's an earlier Superman reference in Playing With Fire, where Valkyrie comments that Dusk ripping off his human skin is similar to how Clark Kent rips off his shirt.