Let's start with the one that not only convinced me I did want to watch GuP, but made me a Sabaton listener as well:
The next two use music from Two Steps from Hell, both from the Invincible album. The TSfH music together with the particular scenes chosen subverts the tone of the series, making it seem grimdark and epic:
And I'll finish off with Manowar's "Warriors of the World United"
Edit: The link I put in for Black Blade was bad. Corrected.