How about User Fragging? All of originaltrilogy.com becomes an MMOFPS running a html5 port of some variant of the Cube engine (Cube, Assault Cube, Cube 2, Red Eclipse, Platinum Arts Sandbox, Tesseract etc...)...
ugh now I'm picturing every thread as an iteration of Ac_Douze, while in Off Topic Frink trolls everybody with a custom map featuring the Mighty LOLBunny and "Friday" playing on a loop in the background.
… And they had ‘The Empire Strikes Back’, the fifth of the four Star Wars films. He is fucking with us numerically, isn’t he! “Children, count up to ten.” “Four, five, six, one, two, three, ten”. No, it goes, four, five, six, one, two, three… No, it goes: four, five, six. One… Two and three have not been made." “Two and three have not been made! What should they be?” “What should they be? We do not know. All we know is that there will be a big floppy character in it that goes, squawk squawk squawk… who needs a punch up the bracket!” - Eddie Izzard, “Circle”, 2000