I'll stick with autoloader companies since this is the autoloader forum.... and not get into revolvers.
S&W - Blame their marketing. Heh... never really paid any attention to them. and with all the great guns out there y start? Oh yeah, and their Sigma's. Ah also... their 1911's, that billboard rollmark kills it. I want a Scandium 1911 from them but not with that billboard advertisement on the slide. Now I know why I have this intense aversion to SW auto's. Blah...
Ruger - Eh, their guns are ugly, ergo's suck, and the one I shot wasn't very impressed by. They're reliable and all... but boring to shoot, look at, and I would assume own.
Auto-Ordnance - The low end junker of 1911's. I've heard enough of them.
Para-Ordnance - Heh, I think I have an aversion to any Ordnance 1911's. This company I found screws up the 1911's too much. Double actions, double stack etc. The one I shot was a jammer. And from my research I've heard more neg. than positives.
Kel tec - I have no need for a kel tec
Taurus - No wonder clones for me.
AMT, Jennings, Ravens, Bryco - They all get categorized by the POS category here.
Springfield Armory - Their 1911's, eh... never really became fascinated by them. From what I've read, they've had a few QC issues out of the box, mainly the sights falling off and shooting low. The Loaded SA I shot also shot low. And it wasn't cuz I was flinching.
The M1A I have, I must say quality wise I'm not impressed. The fiberglass stock is a true junker. And it smells funny.
It does shoot well though.
Rock Island Armory - I rather own a SA milspec than a RIA, and I dont even like SA's.
Llama - Junker 1911
Beretta - My experience with the FS series (92FS and 96FS) has been less than average. The 92FS I shot was a jammer. Maybe a lemon, yes... but how badly it jammed made me want to throw it down the range. The sights I found sucks, and also the triggers I found were really vague. I couldn't figure out for the life of me when the gun would fire.