At first, it was stated with in a game for the Sega Genesis known as "Zero Wing". In which the enemy states "
All Your Base Are Belong to Us." The game otherwise was fine it seems, I never played it truely, but looked up on it.
Later a flash movie was made, in which the intro was the scene the phrase was stated then lead to a catchy song. THe words are only versions of "
All your base" "
all your base are belong to us" and a catchy tune. All the while a flashing of screenshots with the words "
All Your Base" are put in to match quite nicely.
To see this and many other renderings, I suggest Newgrounds.