This ranking is based on the views, like rates, and comments from some playlist statistics. Screenshots are taken from my own play.

Octopath Traveler 2 | 25 Best Soundtracks, Ranked:    • Octopath Traveler 2 | 25 Best Soundtr...  
Octopath Traveler 2 | 15 Best Area/Town Day Themes, Ranked:    • Octopath Traveler 2 | 15 Best Area So...  
Octopath Traveler 2 | 15 Best Area/Town Night Themes, Ranked:    • Octopath Traveler 2 | 15 Best Area Ni...  

00:00 Home of Wisdom and the Arts
01:30 The Leaflands
03:03 The Winterlands
04:44 Hinoeuma
06:44 The Wildlands
08:12 Flamechurch, Sacred Light
09:14 Tropu'hopu, Secret Paradise
10:41 Village in the Ravine
12:00 Toto'haha
13:29 Roque Island, Full Steam Ahead
14:54 Orerush, Pioneer Town
16:09 The Crestlands
17:56 A Sensational City
19:25 A Verdant Wind Blows
21:02 Ku, Land of the Scarlet Sunset

Disclaimer: I do not own any of the songs in this video, they all belong to their respective owners