The journalism in the New York Times is phenomenal, best in the United States, and tied with The Economist for best among English language news sources overall. And -- in my experience -- the further back you go into the New York Times, the better the journalism is.
Obit takes you way back, into the obituary pages of the New York Times. A front page obituary is rare, but in all cases there is a detailed process for selecting who will get an obituary, what will be said about them, and how it will be said. And there are valuable lessons to be learned in an obit. As one of the obit writers says, an obituary says very little about a person's death. It's mostly a celebration of their life.
There's also a lot to be learned about the care that Times reporters put into their work. The guy who runs the storage room full of old photographs and obit material casually told a lot of great stories about some of the old obits he's seen.
I'd happily watch a documentary about the Times business, sports, or entertainment sections. Or just about any section. But the obits seem like a great place to start.