Depends on how you see it though; the most impactful stuff is not necessarily the most reported in the media. As always, the media lags these things and so the public don't get to see shit coming.
As far as I can remember, most important research from OpenAI is InfoGAN. Others feel somewhat below outstanding. Their open source record on the other hand is pretty solid, gym/universe and various implementations and testing of existing models does live up to the openness in their name.