Do you mean when the companies were still relevant, or right now?
Either way, the result would probably be the same: nothing. Amiga's hardware wasn't really designed with game consoles in mind, and Atari's games were't worth much after the 80's.
Well, OK, Tempest 2000 on my Jaguar is pretty cool once in a while. But, damn, that Jaguar boot-up screen is just pathetic. ;-)
