It ain't a favorite, but my P12 Grendel works every time. It ain't real accurate, about 6-7" at 25 off a rest. But, it carries 12 rounds. The trigger sux, but is usable....barely. It's the smallest high cap gun I know of, slightly lighter and smaller than my P11 Kel Tec. It has the neatest heal/clip release I've yet found, neatest thing about the gun. I like the heal release for pocket guns, no chance of accidently dropping the mag if you sit on it or something. It's no longer made and never really popular. It was cheap and hell, like I say, it feeds and ejects 100 percent with ammo it likes. There are better .380s out there, I'm just not really a .380 kinda guy.
I haven't gotten a LCP or P3AT yet, don't really feel the need. One thing, if you find a used Grendel, make sure it's a P12 and NOT the P10. The P10 had a fixed mag and lots of feeding problems which were fixed in the P12 after the gun's rep was ruined. The P12 is a decent gun if you find a used one. I've found mags for it, not cheap and getting rare.
Personally, I sorta have the hots for a 9x18 Makarov since I shot my son-in-law's. Sights kinda suck, but the trigger is okay and the damned thing is shockingly accurate for a cheap gun. It's got more punch than .380, too. I probably wouldn't carry it that much, prefer my 9x19 Kel Tec P11 with 115 grain JHPs at 1262 FPS packin' 13 rounds. It gives me the warm fuzzies.
I've had it and my CCW for about 12 years now. It's accurate and reliable and carries easier than most .380s.
The Grendel:
Kel Tec P11: