The Proper Response: What You Say!!

Most-referenced phrase from the Engrish-translated intro story to the video game Zero Wing. Briefly immortalized on Something Awful in an extremely long forum thread containing posters' attempts (of varying quality) to edit photographs so that the phrase was contained within them. (Example: Family Feud picture with "All Your Base Are Belong to Us!!" as the answer displayed on the board behind the host).

Addendum:

When I wrote the above in late December of 2000, I had no idea how suddenly this one phrase, now officially dubbed an Internet meme, would spread. As of late February 2001, the Zero Wing intro story has been set to at least 5 types of music, mentioned in Time magazine, Photoshopped into hundreds, maybe thousands, of pictures, and subjected to a war over who noted the phrase and started the whole thing in the first place (I still believe it was Something Awful).