The "Painkiller" thread reminded me of a moment some time ago:
Some guy at work started playing Iron Maiden's Somewhere In Time, from his iPlod. It just so happens to be the very first Maiden album I ever got ahold of, probably 1988 or so. I thought it was pretty cool (and it's a great album) but for me it's really just a springboard into some of their other stuff that I absolutely love with all of my very being, including my guitar hands.
Anyways... I know it's a total 80sism, but ever notice how uh, 'synthetic' the guitar tones are on that album? The over the top gain, the chorus, the flange, the gating, all the stuff that probably came from a rack of Alesis the size of the Twin Towers... The chords just dissolve into a low-res mist like a meatloaf fart in the shower with the lights off. The twin leads are slimy, but well defined, but man, all the rhythm work.... sheesh...
Add this in with how overproduced the whole album is, and my first impression of Iron Maiden was as if they were a 'hard new wave band' in the 1980s. Seventh Son of a Seventh Son sort of followed up in the same path, but what took me many years to determine, is that these two albums (Somewhere In Time and Seventh Son) are probably Maiden's #1 and #2 hardest albums, but you just can't hear the dynamic of it through all the churning slurm.