Well there were lots of great ones, but if I was going remix any game song into a modern metal tune :-D , then it would be the Hybris music, both the title and game music
Just love that screaming guitar type lead and the music itself is really well put together!
Close second, Stormlord title music
Oh, and the Batman: The Movie music for the Cathedral level (and the Jogeir Liljedahl remix, I think I got his name right) were really cool too :-)