Auto Ordnance, Rock Island, Charles Daly. Basically I'll have nothing to do with Third World "quality" engineering. An Imbel forged and Springfield assembled 1911 is as close as I have come and it is not a bad gun though internally nothing to write home about.
Plastic, and I have owned or fired all of the big hitters. The P99's trigger seems subcontracted from Nintendo. The Glocks feature a grip angle and finger grooves modeled off of a Roswell, New Mexico, alien dummy. The HK USP is too much for too little and features a "chewed on" feel. Paddle mag releases suck in my experience. However, the XD is growing on me enough to take the plunge into polymer again because of a SA trigger and a good mag release design. I'd also be interested in handling a FN9P, but I have never even seen one.
Kahrs. Almost every one I have seen or handled had something at least cosmetically wrong with it that would keep me from paying the freight. The ones that were okay still featured really bad triggers IMO.
Taurus. Everything they make that holds together for more than a few rounds is a copy of a better original. Nearly everything they make that is an in-house design is an utter disaster.
BHP. Going into its seventh decade of being a next to incurable web-biter. The single action trigger is no better than any more recent wondernine in SA mode. A CZ eats the BHP's cake and costs less.
S&W autos. Functional but fugly. Fired some but never wanted one.
Ruger autos. Worst "American style" magazine release ever. Ugliest looking plastic ever, but at least the new P345 is looking to at least get it to average ugly for polymer and features a normal mag release.
Knock-offs. I have yet to see a clone outside of the 1911 realm that was an improvement on the original manufacturer.
Cheap revolvers. A decent revolver is a wonderful experience, a bad revolver is a nightmare.
Old double action revolvers. I can see the nostalgia in collecting them, but "ergonomics" wasn't a part of the English language when say, the Colt and S&W 1917s were being made. A 1917 in original trim was the most unwieldy handgun I have ever felt, which was confirmed on firing it. WORST GRIP EVER! Were I in the trenches of WW1 I would've traded a lot of rations to have a newfangled 1911 instead.
Anything in .40 S&W. I have no use for that cartridge. If I want a big bore I'll go .45ACP. If I want capacity, I'll go 9mm. If I want a hard hitting medium bore, I'll go .357 Magnum or 10mm.
Anything in .380. What a pointless little round. I'll take a 9mm in a slightly larger package or a .32 in an even more concealable package please.
That pretty much covers it.