I thought the FFIX Coca Cola advertisement (still counts, right?

) was pretty cool.
And the FFVIII one was pretty cool, even if people disliked the game, the cut-scenes were blinding, and that commercial rocked.
But it has to be, the original Japanese Sonic adverts, I think it was Sonic 2/3, where he jumps out of the game box and starts running around, I can't remember what exactly happens, or any links to it, only that it was on Sonic Jam for the Saturn.