I'd say the highlights are the News History gallery on the 5th floor and the related section on Internet, TV and Radio on the 3rd floor. I also really liked the "Today's Front Pages" exhibit (on the 6th floor, with related interactive screen access in the 3rd floor "World News" gallery), which includes pages from papers in various parts of the world. I should also mention the excellent view of the Capitol from the 6th floor terrace.
There are a number of video presentations and interactive displays, which we had to skip due to time constraints. I would definitely go back and try to see more of the exhibits.
We also had to spend time catching up after not seeing each other in years. Getting back in touch was a fall-out from Facebook, by the way. All in all, it was great watching the years just roll away.