If someone were to ask me that hypothetical question, my answer would be a nickel plated .22lr High Standard Sentinel R101 revolver. As a practical carry weapon it does not fit any of the criteria. Unconcealable, too flashy and it’s only a .22lr.
However the question is my favorite carry weapon. This particular High Standard is a Family heirloom gun. Belonged to my Grandfather, passed down to my Mother. It happens to be the first handgun I ever fired and she taught me how. It has been on my hip on countless trips in the woods and my 10 year old Nephew is quite fond of it now. The old girl is showing her age and needs to be rebuilt. That will happen, however I can’t trust it to just anyone. I have since bought my Mother another revolver for self defense, but nothing will ever replace the old Sentinel. It has a place of honor in my safe.
As for my favorite concealed carry handgun, hands down it’s a S&W MP9c. I have no problem wearing it under a tshirt in the summer with the 12 round mag. In the winter I carry the full size 17 round mag, easy to conceal under a fleece jacket. Also, with a spare 12 round mag on my belt and one in the chamber that works out to 30 in the winter and 25 in the summer. Not bad at all for a concealable handgun.
So, what is your favorite carry gun? Concealable or not, every gun has a story.