The very worst was one of those Eastern European Hi Power "clones." ...It did look a lot like a Hi Power, at least!
Bought it and cleaned it one weekend, shot it the next, sold it that evening. Gosh, it was awful. I've shot nice Brownings and okay FMs from Agentina but that thing was nasty: rough, gritty trigger pull, inaccurate even by my low standards.
I was happy to lose a little money selling it. It counts as tuition!
Next worst purchase, a 9mm Norinco take on the Tokarev. It's pretty much a cheap hammer: inelegant, works well enough, a pig to take down and worse to reassemble. That's my beater; that's the one I wouldn't feel bad stashing along with my second-best tinfoil hat in an Undisclosed Location for a rainy day. A very rainy day!
Next worst after that, a poor old, sad Ballester-Molina that had probably been used as an actual hammer! Bought sight-unseen on a "trust me" and paid too much for it. There's no bluing left and I had to file sharp, peened-out edges from the solid beavertail and backstrap before it could be fired without tearing up my hands. The grips looked like they had been chewed on. The grip screws looked like they had tried to chew back.
On the other hand, the old warhorse does still work, probably no worse than it did when it was new. And there's something to be said for owning a "Ballerina Molester." I don't know what that something is, but there must be something? Possibly "Rube!"
--Herself