I'll give it a go
Glock - cop guns, ghetto homeys shoot sideways, fantastic plastic, weird trigger, Bruce Willis knows about the only porcelain one, great customer service, cheap replacement parts, easy for anyone to work on, bury it in the sand, freeze it, drop it out of a helicopter and it still works the same, .40's kb!
Colt - first great pistol, old West, Detective Special, perhaps the best factory (non-custom) 1911
again
Springfield Armory - Decent factory 1911's
CZ - bargain buy, quality machining until you look inside, reliable, underraterd, impossible to pronounce the full name
Magnum Research/IMI - Desert Eagle, the dudes in the Matrix, people in movies carry them everywhere and shoot fine with them all the time
Smith & Wesson - best revolver, cylinder rotates the other way, triggers aren't as good as they used to be, company was loved, then hated, now okay again since they're owned by someone else
Beretta - M9, Mel Gibson's smiley face in Lethal Weapon, really nice and freaking expensive over/under shotguns, oldest name in firearms
Ruger - great buy, garbage eaters, good .22's, GP100 used by ammo companies to test high pressure loads, Bill Ruger is considered by many to be better off resting in peace
SIG, SIG-Sauer - expensive as hell, elite, reliable, rust easily
Taurus - revolvers copy S&W, semi-autos copy Beretta, their own versions are iffy, customer service poor, quality control spotty, great deal for what you get, all shortcomings are improving and so is their reputation
Browning - BHP, Buckmarks, tradition, John Moses Browning pretty important in firearms history
Walther - "The name's Bond - James Bond.", Nazis
Kimber - decent custom 1911's, used by LAPD Swat