Riot - Outlaw vs. Queensrÿche - Suite Sister Mary
Suite Sister Mary is great, but there's a fair few tracks on OM that work outside the context of the album, particularly all the main tracks from The Needle Lies onwards, Suite Sister Mary isn't one of them, it's pretty much the centrepiece of the albums narrative, and I just don't know how you can get that vibe if you are listening out of context. Outlaw is great, what a catchy riff, and very Black Rose era Lizzy vibe from the chorus.
Outlaw
Candlemass - Demon's Gate vs. Metallica - Enter Sandman
Demon's Gate is brilliant but out of it's depth here. Sandman is probably metal's biggest hit, the build up is brilliant, and the fact that the whole song is variations of the main Hammett riff could have left them with egg on their faces, but they milked that one riff so well. The lyrics would be my sticking point, they are awful guff, e.g. "and of things that will bite, yeah", but I accept you have to dumb things down to get a hit. Maybe Hetfield's original cot death lyrics were even worse?
Enter Sandman
Devin Townsend - Earth Day vs. Rainbow - Gates of Babylon
Earth Day is not my thing, Gates of Babylon very much is
Gates of Babylon
Ozzy Osbourne - Suicide Solution vs. Ozzy Osbourne - Mr. Crowley
Suicide Solution is a pretty great track, but probably only better than Dee and No Bone Movies off that album, whereas Mr Crowley is the best track on the album, and maybe the best ever Heavy Metal guitar performance.
Mr. Crowley
Sonata Arctica - White Pearl, Black Ocean vs. Black Sabbath - N.I.B.
N.I.B. is probably the weakest of Sabbath's big name tracks, but a clear winner here.
N.I.B.
Deep Purple - Perfect Strangers vs. AC/DC - Let There Be Rock
A real tough choice here, but have to go with the gut instinct of Let There Be Rock, I kind of agree with
@Black Bart about the length live, but that's when listening to the live album, seeing it in the flesh is a different story and one of my best ever gig memories is seeing Angus up on a 30 foot high platform in the pissings of rain running amok. Perfect Strangers is great too.
Let There Be Rock