GLOCK 42 gets my vote
In a .380ACP pocket carry, the GLOCK 42 is my choice. It has been totally reliable, shoots well with mild recoil for a gun this small and light.
You can often find it right about $400.00. It is my first choice for pocket carry.
The BERETTA 84 & 85 Cheetah are just as reliable, if not more so than the GLOCK 42, but are large compared to the GLOCK and a poor choice for pocket carry.
As a holster gun or low recoil house/car gun, it would be hard to beat. The large grip, good trigger and sights make it a fine, accurate shooter. The choice of a single column or double stack magazine is a nice bonus, but it is not cheap!
My other recommended .380ACP would be the SIG 232. ALSO PRICEY, BUT WORTH IT!
The SIG is a little easier to conceal than the BERETTA, but still too big to pocket carry. I know, because I did it for a while. Really good trigger and sights make it an accurate gun for this size class.
Very good ergonomics. Very reliable, but I have read that it may not be as reliable as the GLOCK 42 or BERETTA Cheetah. I have personally not found a difference. I think, the SIG 232 is still reliable enough that you may never notice the difference. I often choose it as my home gun for the night stand (it has night sights).
The Walther PP and PPK are very well made and usually reliable. The many manufacturers involved make it a bit of a crap shoot for reliability and quality.
The PP is really too large to pocket carry. It is slightly longer than the SIG 232 and about the same height, but heavier than the aluminum framed SIG models.
Several years ago, I went with a .32ACP PPK instead of a stainless .380ACP PPK/S because the trigger action on the INTERARMS made guns was so gritty and the S&W made PPK/S, which had a good trigger and an extended grip tang (important for those with large hands)was $300.00 more than the .32ACP PPK, which was a genuine, German made WALTHER.
I found that the PP was no more accurate than the smaller PPK and due to the different grip design, the PPK was more comfortable to shoot.
A quality PPK or PPK/S should be a good pocket gun, but will by costly and heavier than the GLOCK 42.
I had a COLT Government model .380ACP Lightweight model and it shoot quite well, but was a little bulky for pocket carry. The cocked and locked, single action trigger did not inspire trust with me. I am firmly in the double action/safe action camp.
Good luck with your choice.
Jim