I keep my pistol gripped Mossberg 590 loaded with 9 rounds of 2 3/4" 00 buckshot on a rack under my desk in the recording studio downstairs, which stays locked if I'm not inside. I'm usually awake during the late night/early morning hours(ahh the joys of self employment), and since I do a large portion of my work during this time, this is where I usually am to be found at night. If someone were to
plan a home invasion/burglary against me, chances are, they are after my studio gear. Being in this business, I have had all kinds of people in and out of my home and studio. Mostly good people, but there are a few whom I would not be the least bit surprised to see trying to kick in my door. Therefore, the boomstick generally lives down here with me.
Most of the time, I just keep my Bersa Thunder .380 between the mattresses. When I actually do sleep during the night time, I bring the shotgun up and put it under the bed. Since space isn't so much of a problem in the bedroom, I put the collapsable stock back on when it's up here. I hope to be getting a new pistol, chambered for something other than .380 sometime in the near future, and once I do, that will take the place of the Bersa between the mattresses.
Here is a picture of the shotgun and me taken last summer.
It really comes down to personal preference, but you can't go wrong with a 12 gauge. They are relatively inexpensive, reliable, and as long as you do your part, incredibly effective.