Here's my opinions:
S&B - Sellier and Bellot. Czech made. Very good, both the ammo and the brass. Only problem with the brass is it has crimped primers, like military brass. Remove the crimp the first time you load it, and go on with life. I'd say, probalby half of my 45 brass is S&B.
CBC - Companhia Brasileira de Cartuchos. MagTech. Made in Brazil. Excellent ammo. 45 brass has always worked fine for me. Little bit of trouble with their 44/40 brass, but none with the 45 ACP.
Speer - Made by CCI/Speer. They make loaded ammo. I do not believe they sell unloaded brass. They produce RCBS loading equipment and CCI primers. Everything, with one exception (see below), that I've ever used of theirs has been excellent.
RP - Remington Peters. They have been in the guns-and-ammo game a long time. Very good pistol brass. I don't like their rifle as much as some others, and really despise their 22 ammo, but their 45 brass is very good.
PMC - Used to be Pansung Metallic Cartridges (don't know what the hell they say the PMC stands for, now). Korean made. I've never had any problem with the brass, although I did have some extremely hot 7.62 loaded ammo, once.
Blazer - This is the one CCI product I don't like. Originally, they were attempting to save folks money, so they started making ammo in non-reloadable aluminum cases. With revolvers, that's not a problem, but I don't like the way aluminum cases work in autoloaders. Within the last several years, though, they have been making brass cased ammo, and calling it Blazer, also. So you have Blazer Brass and Blazer Aluminum. Blazer brass is fine, in my limited experience with it (200 rounds, reloaded once).
TZZ - Don't know what it stands for, but it's Israeli. Same brass as IMI (Israeli Military Industries), just a different headstamp. All I have seen has been military brass - TZZ and a year on the stamp. All of it is crimped primer. Very good brass.
WCC - Western Cartridge Company. Great brass. All I've seen has been military - ain't seen no civilian with a WCC headstamp, although I have seen Western headstamps. Also all crimped, and I don't think there has been any of this stuff come along since the 80s, and maybe earlier.