Ariat, Noble Outfitters, and Smartpak are all good brands. But, it really depends on you. Everyone has different styles and preferences
Pikuer, animo, ariat, equiline
Kind of a cliche answer, but i personally like Ariat and Dover. Usually I wait for the Dover things to come on sale, and stock up then lol
Aztec Diamond, Premier Equine, LeMieux (do nice socks), & I like using Sweaty Betty tops/sweaters (not equestrian specific but exercise clothing nonetheless).