My dogs will always wear their collars as much as possible.
For quite a while I was adamant that Eve should have her collar off whenever we weren't going somewhere. I am a very responsible dog owner, I would make sure she never got out unattended, I didn't want her to strangle herself inside, etc. etc. etc.
When I was in Washington, I went to run a couple errands and I left Eve and Buddy in the backyard, with a 6' EXTREMELY dog-proofed (and gates padlocked) fence around them. Halfway through my errands I get a phone call from a guy who says he has my dog, and witnessed her almost get hit by a car. End errands, have heart attack, continue to have heart attack while going to get dog. Cry, hug dog, thank the super-nice guy, go home, check the yard, and realize that the only way she could've gotten out was to have jumped 6'. She's barely 25lbs and I had no idea she could jump so high. I thought she was safe in that yard for 2 hours but oooh was I ever wrong. I am SO thankful that she was wearing her collar and ID, because otherwise I'd never have found her so quickly and (it makes me shake just thinking about it) might never have found her at all. A microchip is great, but someone who finds your dog can't contact you immediately if there is no visible form of ID on the animal.
I totally understand the concerns of having a collar on in the house/when unattended, but after losing the love of my life when I was so convinced that an accident like that would never happen, I always want her (and all my future dogs) to wear ID. Jmo!
When I supervise her and when she's playing with the other dogs, I take her collar off. When she's crated and I'm home, I take her collar off. When she's swimming or being groomed it's off. Otherwise it stays on.