David Zwirner have really slick online viewing rooms, divided into their current or past exhibitions. The viewing rooms are successful because they are really visual. A well thought out media led experience. Not much text, the images are beautiful and videos short and to the point.
See the viewing rooms here.
A great source of information and art entertainment is the podcasts series, Dialogues, created by the DZ team. In each episode, they have paired makers and thinkers to discuss the art, ideas, and current affairs.
Click here for the David Zwirner podcasts.