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Not much of a Nightmare fan?
I think that album had their greatest musical diversity, while still keeping the heavy metal sound that they're known for. It's got classic heavy metal style songs (Nightmare, Danger Line, etc), it's got Metalcore (God Hates Us), it's got ballads (Fiction, Tonight the World Dies), it's got a song written as a tribute to their dead band member (So Far Away), and it's got a song that combines all of those styles (Save Me, which is, imo, one of the best album closers). Their other albums, especially avenged Sevenfold, had lots of diversity (like string arrangements in City of Evil and Avenged Sevenfold, whatever A Little Piece of Heaven is, and even a country song). But Nightmare had more overall instrumentation in all of its songs, and a very diverse one at that.
I like your list mostly, though.