Just as planned!

[Azure Chrysanthemum]

So I've been browsing TV Tropes recently, and thoroughly enjoying myself. So, my question to you all is, what's your favorite tired old trope that gets used in whatever series?

Personally, I favor the Xanatos Roulette, as immortalized in the series Death Note.

[JKTrix]

Chekov's Gun is probably my favourite--where an element is introduced early in the story, and its importance (often huge importance) isn't revealed until much later.

TVTrope link