Metallica without a doubt. Makes no difference to me what happened after the Black Album and the whole Napster mess. The early stuff is still unmatched by anyone in my mind.
Oh, and a sidenote that the S&M album totally rocked (not everything after the Black album stunk
)! Just added so much to the music (and I didn't think that was possible), that both CD's in the set stay in my rotation no matter what.
I am the Reaper of Men,
The Chaser of Souls,
The Weaver of Nightmares,
I am The Heart of Darkness.
I now, and ever will be,
The Purity of Evil.