I felt sorry for a guy that needed money back in the 80s. It would shoot okay, till either the linkage to the main spring, or hand, I can't remember exactly, would come undone and I'd have to fix it.
I've previously owned a couple of Taurus revolvers that had less that stellar QC on the finish, etc, but they never failed mechanically.
Other than those I can't think of anything. I've always researched firearms, carefully examined used ones, sometimes talked to other owners and stuck to quality brands. Since the internet got in full swing though, its too easy to find out which models and brands are causing problems. Not much excuse for being uninformed.
"No free man shall ever be debarred the use of arms."- Thomas Jefferson