Indie games in general have great OSTs, MGS:R and Persona (and SMT in general) are obvious popular picks.

The World Ends With You is less mainstream (with one of the few gripes being the lack of boss-specific themes, at least in the DS original I played - but it makes up with the diverse overworld and normal battle themes), as is Etrian Odyssey.

I think orchestra is mixed, it’s either the best fucking tracks ever (often when mixed with electric guitar or other modern instruments, but not necessarily), or they kind of blend with other orchestral tracks I know and don’t end up being unique enough to remember.