I'm actually most drawn to the Marik-Stewart Commonwealth, largely because of a couple factors. First, they're the province that is actually the seat of FWL governance, containing Atreus itself. Since I fancy myself a supporter of the federal government ahead of any one province (or family, for that matter), this matters a fair bit. Second, they give us three of the best designs to ever grace to rolls of the FWLM in the form of the R10 Mechanized ICV, the greatest infantry combat vehicle ever devised; the Anzu, one of the greatest heavy troopers ever conceived; and the Juliano, one of the best Assault 'Mechs ever made. They also designed and produced the Seleucus DropShip, one of very, very few dedicated infantry carriers in the game, capable of carrying a company of light vehicles (likely R10s, if they have any sense at all) and a full FWL sized battle armor company of 20 squads.