Nope. If I'm not ready to fire, it isn't loaded. If you want to carry a loaded gun, that's fine. Leaving one lying around--even in the safe--doesn't appeal to me. Even when I was in Afghanistan, we didn't keep everything loaded all the time. Outside the wire? Yep, always got one in the pipe. In the chow hall or in my "room"? Nope. Mag in the mag well, but nothing in the pipe. If the baddies decided to rush the wall, we would have had time to chamber a round (and put armor on, get NVGs, wait for plan of action from PL and SL). Only happened twice, and both times the baddies were persuaded to leave by a pair of A-10's flying over to say hello.
If the zombies come for you, you'll probably have time to slap a mag in and chamber a round. Well, as long as they are slow zombies like in Shaun of the Dead. If they are fast zombies like in 28 Days Later, well, maybe you do need a mag loaded.....