Favorite house for me would mean one from which I've found a handful of scents that greatly appeal to me, as opposed to a house from which I've only found 1-2 favorite scents. Take into account I have not tried every scent offered by the houses, yet.
As of now (I can't pick a single favorite, I love them equally):
Serge Lutens: Muscs Koublai Khan / Chergui / Ambre Sultan / Cedre / Fille en Aiguilles + many more actually.
Parfumerie Generale: L'Ombre Fauve / Felanilla / Cuir d'Iris / Iris Taizo
Montale: Attar / Black, Red, White Aoud / Oud Cuir d'Arabie
Creed (If we consider it niche): Silver Mountain Water / Virgin Island Water / Erolfa / Green Irish Tweed
Tom Ford (If we consider it niche): Tobacco Vanille / Japon Noir / Noir de Noir / Amber Absolute / Tuscan leather / Italian Cypress / Black Orchid
Honorable mentions:
L'Artisan Parfumeur: Vanilia / Fou d'Absinthe / Tea For Two / L'eau du Navigatuer / Havana Vanille
Etat Libre d'Orange: Tom Of Finland / Rien / Eloge du Traitre / Vierges & Toreros / \tVraie Blonde