re: Best piece of music from any movie ever

I just don't know how it's possible to top this.

Rebel Fleet/ Ending Credits

A seamless, striking medley of some of the trilogy's most iconic leitmotifs.

The short but incredible "Lighting the Beacons" sequence from Return of the King is a strong entry too.

Howard Shore's best work

I refuse to shy away from the most effective themes or composers just because they are "obvious". John Williams is the best of all time when it comes to traditional symphonic scores.