I've thought about this a lot. It shouldn't be like a PDF file: left/right and nothing else. My favorites from the usability are:
News: USA Today
They have the usability pretty close to perfect in my view, but I always feel like there could also be more content that you can't just find on the web: I want to know how something makes someone feel with lots of minutiae, opinions pro and con and insider info. What the web is often missing is depth.
Nail both the content and the usability and you'll have a win.