Metallica by a hair. I love everything Metallica did up until Load/ reLoad. I just couldn't get into those songs. I was in the minority but other than the horrible snare sound I liked Saint Anger. Death Magnetic is what I thought they would sound like at this age, pretty cool.
Megadeth was great too, but Youthanasia rubbed me wrong. Overproduced, with no edge. Cryptic was okay but sounded like leftover b sides thrown together to fill a contract. Risk was terrible. Hero was not much better. Maybe a couple of ok songs. System was getting better with a few more but the majority were still bland. United was better yet, but still not a buy for me. It wasn't until Endgame that I felt songs were back up to par. 13 is cool, but not quite as good as endgame.
I guess it comes down to who has fewer clunkers and Metallica wins that contest. Metallica is a better live band as well. Dave is lifeless on stage. He reminds me of Dylan live. Lately Dave was doing the high notes falsetto which pretty lame. I could do without the 30 minute solos Metallica insists on, but they are just more fun, and look like they actually want to be on stage. Dave is a bigger prick than Lars. Dave chooses to be a prick. Lars was just born that way.