Under rated is an often misused less common or less known would be better, quite often brands that people mistakenly class as under rated are in fact rated very highly by a smaller and loyal market segment.
Heres a few company tress to help you understand some of the bigger brands:
Salomon / Atomic = Amer Sports group - all of Armadas skis are manufactured buy Atomic in Austria.
K2 brand group: K2 , Marker-Volkl, Full Tilt, Line.
Look / Dynastar / Rossignol / Lange, are all part of the same group as well.
Technica group: Blizzard, Nordica, Technica.
Out of the majors there's a few more standalone brands like Fischer Sports and Scott Sports.
Theres plenty of highly rated small companies out there making some amazing stuff heres a few to check out: PMgear, on3p, Praxis, Prior, SPUrat, RMU, Moment, Black Crows etc etc
Usually to be found working in the alps with 'Staff' on the back of my jacket pretending to know whats occurring while I slink off to go ski.