For me,the Lorcin L380.What a piece of doo doo!
Long story short,before I knew squat about quality firearms,while firing it,the slide broke off,flew at my face and hit my chin and needed stitches.
I know the Lorcin L380 has been resurrected by Cobra as the Cobra Freedom FS380.Not sure how much better they are from the old Lorcins.
I had a Bryco Jennings 59 that never broke,but I sold it and specifically told the buyer I am not responsible if it fails.I once fired a friends Jimenez JA9 (a reincarnation of the Jennings 9) and it was a jam-o-matic nightmare.He paid $179 for it and he finally sold it and bought a Glock 19.
This isn't my Lorcin it is from another forum but this is exactly what happened to mine.
These guns are more dangerous to the owner than they are a criminal.