vanchann: Among those four, it's an easy answer for me "Megadeth". If I had to choose an album too, it would be "Youthanasia".
Looks like the discussion is about American Bands only. Things could have been different if Sodom was on the list! :-)
darthspudius: Good choice. Personally I love that album and Risk. They're different.
I like "Countdown to Extinction" and "Cryptic Writings" too. "Youthanasia" is chronologically in the middle and combines the sound of both.
Emob78: Nightwish. They're from Sweden. And you Europeans think we 'Muricans don't know good culture! Pah!
Randalator: Aaaaah, Nightwish. Truly the most brutal Finnish Thrash Metal Band from Sweden.
Really interesting classification!
So, Nightwish is not a Finnish Death Metal band from Italy... :-)
I love (ex-Nightwish) Tarja's voice by the way.