Shadows is the current top dog. It has a lot of steal, elusive, removal, and a good amount of raw aember generation.
Sanctum creatures are the biggest bullies of the board. Their above-average power and armor means that most low power creatures your opponents control won't have a significant impact in combat.
Mars seems like a really strong house. There are some competing forces within it though.
Brobnar is big and it wants to fight. It is the house with the most powerful creatures and the highest average power.
Logos is a very consistent house. I think there are a lot more B's in this house than Dis and Brobnar but there aren’t any cards that are just amazing by themselves.