Seeing as this has turned in to a "show your 9mm Browning" thread.
My First 380, purchased new (surprisingly enough, I still have the box):
Colt 380 Government model
This is the only pistol that I have ever used for personal defence. However, I never fired a shot, in fact, I didn't even remove it from its holster. I don't carry t because I feel odd carrying an out of production pistol.
In addition, I frequently found it with the safety off when I know I holstered it with the safety on. I never considered it to be the biggest of all possible problems, after all, it has a firing pin block, but it did give me cause for concern.
Not a 380, but real close:
Makarov
This one is in 9x18, the ammunition is available, but a bit obscure. I detail stripped it and polished all mating parts. The result was a significantly better gun than I had started with. However, it is a bit heavy in comparison to the others on this list.
Being a blowback pistol it also had more felt recoil than there others here. It, being a blowback, is a bit hard to charge due to the heavy recoil spring.
I purchased when I returned to the states and my Colt was on the other side of the country:
Glock 42
I really can't say why this one never became a favourite. I have really tried to like it. It is large enough to get a good grip on it. With practice, I became reasonably accurate with it. I just never "bonded" to it.
One complaint I have with it is that it is very hard to charge. The recoil spring is very heavy and the slide is coated with a finish that would be appropriate to non-stick cookware. I eventually added a product that is essentially state board tape in the cocking serrations. That change made it a significantly more serviceable pistol. However, by that time I had just lost interest in it.
For some reason, I don't seem to have many pictures of this one:
Walther PK380
Another one that I should have liked, but didn't. The easy charging slide addressed my, "hard to charge," complaint about the Glock 42. The long double-action trigger pull alleviated my discomfort about the Glock trigger system. But I never really like it.
I think the problem was that, for what it is, it is a very wide pistol. It also looked like a pistol that was intentionally limited after its initial design. Looking at it, it is obvious that it was initially designed to have a double stack magazine. Then somewhere along the way, it was decided to market it as a single stack. As such the mag well is filled with spacers.
For a 380 it is a large pistol, I am okay with that, however, it could be a bit slimmer.
If it had a grip safety it would be perfect:
Kimber Micro 380
I honestly feel that if this one had a grip safety it would be great. The Kimber Micro 380 is one of a large family of pistols that are based on the Colt 380 Government Model. All of the sudden the market was flooded with versions of this pistol. I suspect it has a lot to do with the expiration of several patents on the Colt 380 Government Model. This pistol is so close that the Colt 380 Government Model slide can be put on, and used with, the Kimber lower. The opposite is also true, the Kimber upper can be used on the Colt lower.
It addressed one complaint I have with the Colt 380 Government Model, which is the poor quality of the Colts sights.
I think because I started with a 1911, that I just expect this type of pistol to have a grip safety. In all the Micro 380, and its siblings from other manufacturers is a great pistol and I would not hesitate to recommend it. The only issue is that being a single action, the user needs to be very comfortable with the manual safety.
My current preferred carry pistol:
Browning 1911-380
For a 380 this, like the Walther, is large. If a person is comfortable with that, and with the 1911 controls, then this is a great pistol. It is only a small amount smaller than the Walther in High and length but feels much thinner.
This is my most commonly carried pistol. The sights and trigger are good, I am not going to repeat all of the reviews here, however, it is also one I would recommend to someone that is comfortable with the 1911. Internally is much more similar to the standard 1911 than the Colt 380 Government Model family is.
It is swapped out with the Kimber at times due to its size.
As far as the efficacy of the 9x17 for defensive purposes, all of the statistics I have seen tell me that it is adequate.