Regionals may have a few good deal schedules, but those will go senior... so you either have to bypass upgrade to get them as an FO (dumb in this hiring climate), or stay for many years to hold them as a CA. For junior folks, the best way to get sweet overnights is to find them embedded in an otherwise garbage 4-day.

As others have said, the majority of regional overnights will be at a La Quinta on the airport frontage road, across from a chevron and a McDonalds.

Skywest used to have some decent overnights in the inter-mountain west, some of those small towns are fun. I even skied on a JAC overnight once, gear and lift ticket comped by the hotel. For the most part I'd count myself lucky if there was a decent running trail or a mall with a movie theater nearby.

Majors have better hotels, and generally more good overnights but again seniority is king there too. I've had some international overnights that were full-on mini vacations, if you wanted to get out of the room and take advantage. Also if you're willing to do red eyes, anything might be possible...