Hall of the Mountain King would be better without "Strange Wings" and "Prelude to Madness". Cirith Ungol's and Blitzkrieg's covers of Bach's "Tocatta" are far more tasteful 'metal' renditions of classical pieces, just off the top of my head.
I agree about Prelude. I always liked Strange Wings, though. Sure, it's the poppy commercial song, but it's pretty catchy. It's placement in the tracklist may be imperfect, however.