What's a non-hardstyle song that you think would sound great in hardstyle form?

Ever since I first heard Empyrean by Mike Oldfield, I always thought that the melody would sound fantastic as a hardstyle track. Though the original track itself is very short, I still love the composition and I think there is so much potential to build upon in a remix or bootleg.

But I also want to know of any existing songs that you think would sound good incorporated into this genre?