Damn, that's a hell of a question to think about. So many classics come to mind. These are some of my favorite classics. Mine tend to be more obscure to the general audience. Sorry if this seems like a wall of Youtube vids.
"Phantom of the Opera" - Iron Maiden
"The Real Me" - The Who
"Battle Hymns" - Manowar
"Hall of the Mountain King" - Savatage
"The Great Misconception of Me" - W.A.S.P.
"Keeper of the Seven Keys" -Helloween
http://www.imeem.com/rizkallah/music/tzF9TD78/helloween-keeper-of-the-seven-keys/
"Phantom of the Opera" - Iron Maiden
"The Real Me" - The Who
"Battle Hymns" - Manowar
"Hall of the Mountain King" - Savatage
"The Great Misconception of Me" - W.A.S.P.
"Keeper of the Seven Keys" -Helloween
http://www.imeem.com/rizkallah/music/tzF9TD78/helloween-keeper-of-the-seven-keys/