I'll give you some of my personal favorites.
As far as classic metal goes you should try Iron Maiden (The # of the Beast, Piece Of Mind and Powerslave), Judas Priest (Screaming For Vengeance, British Steel and definitely Sad Wings Of Destiny), Motorhead (Motorhead and Ace Of Spades), Accept (Metal Heart and the one with "Balls to the Wall", which I don't remember the title), Saxon (Strong Arm Of The Law), Ozzy (Blizzard Of Ozz and Diary Of A Madman), Dio (Holy Diver, Last In Line), Tokyo Blade (Night Of The Blade).
If you want something more epic then you should try something from Manowar (Hail To England, Into Glory Ride), Virgin Steele (the last one Visions Of Eden is pretty amazing actually) or maybe Rhapsody (especially their debut and their latest Triumph or Agony).
Now if you want to try somethign more heavy then maybe some thrash metal with Exodus (Bonded By Blood), Metallica (Kill Em All and Ride The Lightning), Slayer (Hell Awaits, South Of Heaven and their latest which again I can't remember the title), or maybe Testament (Practise what you preach) or Kreator (Pleasure and Pain).
I could go on forever with sub genres but you are probably already thinking that I am a weirdo, so I'll stop here
Oh yes And I forgot to mention the best band after maiden... Therion. Just listen to Vovin and you'll be blown away. If that doesn't convert you I don't know what will.

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Jeep DJ