I have thought of this before, and I have always wondered why airlines don't get into the hotel business. I mean they spend millions each year, why not start some type of crew quarters like has been mentioned.

#2 would get my vote.

For me, I would actually like to stay at the airport on overnights provided:

There are shuttles (or crew cars) provided by the company to downtown or other areas of interest.
Per Diem is raised.
Company chef provided. Just kidding, sort of.