Thats a hard one, and i dont think you could determine that, just because everybody likes something different. There's better stuff to my ears, but i'm gonna say Stairway to Heaven.
damn i forgot to include dave & al pitrelli's trade offs in the live version of she wolf. it gets really intense feeling and ends with a 2 minute drum solo, then they kick right back in the rest of the song. its great
YJM-Anything from Rising Force, but Far Beyond the Sun is my fav.
RR with Ozzy-Crazy Train is great, but Crowley is a masterpiece.
Alice In Chains-Man In the Box
Blackmore-Highway Star, Strange Kind of Woman and Gates of Babylon.