Personally, I'm a huge fan of Hollow Knight, Ori and the (Blind Forest/Will of the Wisps), and Kingdom Hearts. Orchestral soundtracks are just something else...
I saw Pyre in another comment and honestly, I'd just go ahead and say everything Supergiant has made has top teir OSTs. Bynn the Breaker and Zia's theme from Bastion, In Circles and The Spine from Trainsistor, In the Flames and Bound Together from Pyre, In the Blood and River of Flame from Hades all incredible songs. Supergiant has too many bangers to list across everything they've made