Lavendar Town Reversed - Weird/Creepy music. I find it is dramatic whilst being creepy.
Lux Aeterna A more tragic version of the well-known Requiem for a dream. Good for a somber (no necessarily dark) adventure, awe inspiring and tragic at the same time.
The Shire Celebratory/Peaceful in music. Good for PCs returning home after completing a trying quest, or to highlight the beauty/peace of a location, like a forest.
Baldur's Gate SoA Theme Bold climactic song for heroes rushing into danger.