When outside of my home state (Illinois), I usually carry a 9mm of some configuration. My Hi-Power is my weapon of choice, but I have quite a few others to chose from (Kahr CW-9, S&W CS9, Ruger SR9c, 9mm 1911). I have a couple of .45ACP 1911s, but I don't carry them as a matter of course.
I also have a SIG P232. Which is quite a little tiger when loaded with Buffalo Bore ammo. Which is the only ammo I would use for self-defense in .380ACP. And, if you were to shoot that stuff in the latest crop of really small .380s, you might wish you hadn't. So, I guess I'd have to say that I would only use a .380 if it could be safely, and uncontrollably used with top grade ammo like the BB. Yeah, some will say that you can't safely use it, but you can in a quality, sturdily built weapon. SIG, Walter, are a couple for sure. I don't think I'd trust most of the rest of them.
My real weapon of choice is a S&W M25, 4", in .45Colt. However, it's not exactly easy to carry concealed. Hence, the 9mm and the SIG.