Mine are always in cases. I love the cases so much, I hang them on the wall with Case Contraptions so that I can look at, and enjoy the beauty of the case design.
As soon as my unpleasant guitar work is done, those guitars go right back in the case, and the case gets hung on the wall so that I can reach for it whenever I need a hug.
There's a rumor that a case should be kept in a case cover, and I heartily agree, but it's hard to find a case cover that's as awesomely cool as the case itself. So, a dilemma. I also collect accordion cases, but they're a little harder to hang on a wall, because they stick out so much.
I would keep all my clothing in suitcases, and hang them on the wall, too, but my wife is already objecting to the accordion cases hanging in our bathroom.
In all seriousness, I do keep them cased, I've found over 45 years of playing that it keeps the guitars in better shape, and more ready to play, with fewer adjustments than if I keep them out.