What is your favourite Hard Rock or Metal song of all time? [I Love Music Especially Metal and Hard Rock]

I must admit I am quite a Hard Rock and Metal fan. I really enjoy bands like Five Finer Death Punch, Godsmack, Disturbed and others like them. My favourite song to-date for so many reasons is Jekyll and Hyde from Five Finger Death Punch found here: https://youtu.be/HCBPmxiVMKk

I am keen o find some more awesome songs like this. What is yours and why?