What a tough question!!!
Sheesh, for me it would have to be a close call between a few of them.
Of This Insanity - Because the lyrics reflect a real dark side of humanity, and the riff's absolutely shred.
One Thousand Pasts - Another deep lyrical moment, and one of the most chaotic songs I've ever heard.
Lately though, I have to say that some of the new stuff we've been jamming is turning in to my favourite Fury material.