I think it has to be EA because Atari as I think of it was just a company that launched the success of home gaming but mismanaged themselves into bankruptcy, putting a pretty big dent in the north American video game industry in the process, but a dent that Nintendo very easily fixed with the NES only a few years later. The subsequent uses of the Atari name and IP by successive owners doesn't really do anything but make me sad - I can't really attribute anything that Atari does these days to the company that did all the good (and bad) stuff in the 80s. More like Bernie from Weekend at Bernie's, being trotted out by companies hoping to capitalize on long-dead goodwill.

EA, on the other hand is the same company that started back in the 80s; they have an unbroken bloodline from the scrappy company making good quality computer games that hit the jackpot with their sports titles to the behemoth they are today with all the shitty practices we all know and hate. They are the company that lived long enough to see themselves become the villain.