I would say that in skilled hands, 99.8% of the time a 5 shot .38 special J frame will do the trick if you play statistics.
I carry several guns depending on the time of year and what I am wearing. Today, it's polymer 9mm with a 17 round magazine under an over-shirt. When it warms up, I might only be able to tuck an LCP in my back pocket. Not ideal, but 7 rounds of .380 is better than nothing.
That said, if you absolutely forced me to pick my favorite carry piece and made me forsake all others, it would be my 2.25" SP101 in .357. Now, I know it's bigger than a J-frame, but I don't shoot a J as well as the heavier SP. I generally prefer to wear it on an OWB holster in the winter months when I can throw a sweat shirt over it, but in the fall and spring it slips nicely into the slash pockets on the old light weight barn coat I wear out and about when I go for a walk with my family.
I'd pick it for a few reasons. I can actually hit what I'm aiming out out to 10 yards pretty easily, it packs a good punch, it's there in my pocket ready to go with my hand on the butt most of the time, it doesn't print like a semi, and if I find myself deep in the blood and guts with an empty gun and an assailant within bad breath range it makes a hellova club
I pack a lot of guns I feel at "better" than the snubbie most of the time. Weight, capacity, etc. But if I'm in a hurry and can't be bothered to thread on a holster or find an outfit that hides the contour of my 9mm or 1911, I feel totally fine with nothing more than that 5 shot snub nose resting quietly in my jacket pocket.