Top of my list is a Dan Wesson CBOB in .45. It was not reliable. I shot about 400rds of 230 grain FMJ factory ammo. If would not feed right. I read a lot on the forums concerning the small things to look for on these guns. Sometimes the slide stop would activate so I re-contoured the inside of it. The hammer strut was hitting the inner side of the grip safety. When the trigger was pulled the grip safety would go in a little when the strut moved out of the way. I bought a after market strut and fixed that. Tritium insert on front sight flew out at the range. I called and spoke to CS about the reliability and they would not pay shipping to return it. I traded it off at a loss. I will never trust any DW 1911 again, I don't know why people spend so much for them. When I got mine dealer was around 800, now they are much higher.
My first revolver was a Late generation stainless Dan Wesson. With jacketed ammo I would get hit in the face with bullet pieces or powder particles, I do know which but it hurt. Sold that one for what I had in it. I have collected a few S&W revolvers since and have never had that problem.
I made an impulse purchase of a S&W M&P in 9mm. I bought a bunch of upgraded parts and accessories after a short range trip, VTAC sights, mag extentions, APEX sear kit. After doing more shooting I discovered that I did not shoot it as well as my other pistols. Even others who tried it could not do all that well with it. Sold it off. I really wanted to like it, gave it many chances but it just did not work out for me.