Starline
Well, if you'd asked about RIFLE brass, I'd have said Winchester, but since most of the brass I buy (read: when I can't pick it up for FREE at the range) is bought as components, instead of brass saved after shooting up factory ammo, Starling is just fine by me. I'll shoot about anything if the brass price is right, but the Winchester rifle brass seems to be softer than Remington.
That's not a scientific answer - just seems my Rem reloads tend to crack more often than the Winchester stuff.