Metallica
Slayer's first 3 are sexy. Only really particular songs are very very good, after the "Reign In Blood".
And even "Load" is a masterpiece. Yes it is.
Slayer produced 2 masterpieces, Metallica produced zero, zilch, nada, nope, nuh-uh, next. 4 real close ones, but not even Ride the Lightning makes the cut.
While Slayer is good, they're not memorable. Reign in Blood is great, but other than that, every album has just been slightly above average (with the exception of Undisputed Attitude, Diabolus and God Hates, which just sucked).