The name has already been mentioned...
...but to answer the original question truthfully, out of every gun I've ever owned, by FAR the worst is a Jiminez 9mm. PLEASE understand that I never ever would have purchased that gun, it was given to me by a friend who decided he didn't trust himself to own a gun (probably made a good move there, he certainly shouldn't trust his taste/judgement in purchasing the right one either!) WHAT A PIECE OF (insert your favorite bleepy-word here). I'm not even sure if the original owner had ever even fired it, it showed absolutely no signs of use or wear. I could tell by the PLASTIC TRIGGER that this thing was low-quality, but I took it to the range to see what it could do. WOW... so where to begin, guess I'll start by saying that the 3rd round I ever fired through the gun caused the loaded-chamber-indicator to fly off and land somewhere behind me....
It is a striker fired gun (that I would NEVER carry chambered, or at all for that matter
) and the loaded chamber indicator was an orange cap that was attached to the striker itself, so through a port-hole located where the hammer would be, you could see if the striker was cocked or not. I was not amused, but not really surprised either, when that flew off three rounds in. Regardless of that, the gun consistently shot 6" to the left at 30 feet. For those who may think that could be my trigger-pull, I know myself well, and when I 'yank' the trigger, it places my shot to the right of the bullseye, never to the left. this gun shot way too far left at way too close a distance. The plastic trigger pulls like absolute junk, and the handle itself has sharp edges that dig into your hand painfully with each round. This 9mm is far more painful to shoot than my 4" SW .44mag! Also, the slide is made of zinc, and could basically break and fly off the gun with any given shot. This POS hasn't left my safe since that first range trip.
I'm waiting for an opportunity to melt it into an ash-tray!!!