A trend in recent years is for the NTSB to harvest what used to be labeled 'non-pertinent conversation' from the CVR. In the Colgan 3402 mishap a decade ago comments on commuting and sleeping in the crew lounge were included in the CVR transcript and even read into the Congressional Record.
Apologies for the thread drift, but in the case of Colgan 3402, IIRC wasn't root cause determined to crew error basically caused by excessive fatigue of the flight crew? I think you could make a pretty good case that the conversations regarding commuting and sleeping in the crew lounge were very pertinent with respect to crew fatigue.