I always, always have my pistols loaded and chambered except when I unload them to clean them, otherwise maintain them, give them to someone else for inspection, lock them up, or run out of ammo.

Which means that they are loaded and chambered all the time, unless I *need* to unchamber/unload them, or it couldn't be prevented because I didn't have any bullets left. Never the reverse.
I can't think of many acceptable reasons for not having a round chambered all the time with a modern pistol, except as I say above. With my SR9 I put the manual safety on and don't worry about it. I bought both my pistols because they had manual safeties for exactly that reason, so I could keep them safely in Condition One.
There was a funny line in Lethal Weapon a long time ago: "Do you sleep with that thing?" "I would if I slept."
Well, I'm not Martin Riggs but I have slept with my SR9 loaded and chambered with the safety on under my pillow more than once. It's not really that brave a thing to do: it's got a manual safety, a tongue on the trigger and a striker blocker. Not to mention that you could leave the magazine slightly ajar and have a fourth level of protection, with the gun right under your pillow with a round in the chamber.
You're going to have to be doing something really supernatural in that bed -- while you're sleeping! -- to make the gun fire. I don't advocate it but I've done it a couple of times because I felt I needed to, and I didn't lose any sleep over having the gun there, in that condition.
Obviously if there are children in the household or some other concern not listed here, YMMV and should vary. If you're having friends over, if strangers are coming into the house, by all means, unload the gun. Don't leave one laying around where someone who doesn't/hasn't understood gun safety might pick it up.
But in a carry situation, +1 to everyone else.
Also, let's not forget the first rule of gun safety: You always treat every gun as though it was loaded, and I'll amend that to include: "Loaded and chambered." If you train yourself to consider all your "pick-up-able" firearms loaded and chambered all the time, you internalize the safe handling automatically, even if they're not. It's good practice to think that way, because it forces you to think of safety every time you pick one up or have one on your person or your vicinity/control. Is the gun there? Consider it loaded and chambered.