I tend to favor classic metal simply because it is more melodic (actually its sometimes surprising how mellow some of the old stuff sounds compared with modern metal) .. but I'm occasionally surprised by new stuff that manages to combine the technical skill wizardry of today with actual chords and note progressions
I dunno... I consider Wolfmother (an Aussie band) to be "metal" -- so I suppose we could fudge about on what is metal and what isn't. Some of Muse's and System of a Down's stuff fits the label, imo, as well.