The building blocks of science fiction
Topatco's Periodic Table of Sci-Fi Film and Television belongs on every geek's wall.
Long before the Downfall meme there was the periodic table, a format infinitely adaptable to cultural reference and parody. And yes, like Downfall, it's become a bit played out. Nevertheless, every now and then another spark of brilliance appears, or at least enough cleverness to make you LOL.
From the Roddenlucathine group, which includes the Star Trek and Star Wars oeuvres, to examples of how nonincluded works are molecules--2Ol (Outer Limits) + Dr (Dr. Who) -> Torchwood--there's boatloads here to laugh at and argue about with your fellow geeks.