Right in the center of Falealupo-tai village, Saupesepese Beach Fales offers five fale. The beach is lovely.
Tanumatiu Beach Fales, 800 meters southwest of Falealupo-tai, is on an even more spectacular beach with more privacy. The two fale with mats on the floors are adequate. It's run by the Gisa Seumanutafa family; they can supply buckets of water from their home a few hundred meters away.
Take good care of your gear if you stay at either of these as thefts have occurred. Tanumatiu and Saupesepese are both run by the same family.
One of the few regular hotels on northwestern Savai'i is the Vaisala Hotel, four km west of Asau on the north coast. The 40 rooms in a cluster of European-style buildings face a nice beach. Ask for a room with a balcony overlooking the beach.
The accommodations are good, with private bath, coffee-making facilities, and fridge (but no cooking). Breakfast and dinner are served in the restaurant.
The Vaisala makes a convenient base for exploring the northwest coast by rental car but it's well off the beaten track and sometimes appears a little rundown. The newer Auga Seaside Resort just east has 15 more upscale rooms.