Hey there,
I have very similar interests in the metal side of things - big time metallica fan as well. I have not found anything recently that caught my metal interests. Some old school Iron Maiden (Piece of Mind) or Black Sabbath sound pretty good on the Axioms.
If you like AIC, what about Soundgarden? Badmotorfinger is a classic.
For more recent music - Have you considered Porcupine Tree - they have some metal-ish elements in their songs, but some melodic as well. Their songwriter Steven Wilson produced a few Opeth albums, nad the lead singer of Opeth (Akerfeld?)sings backup (not growling) on their "Deadwing" album, which is pretty heavy. Also, "In Absentia" and the recent "Fear of a Blank Planet" have some heavy riffs. I highly recommend them.
System of a Down have some good songs with a tongue in cheek mentality to boot.
Hope this helps your quest for metal!
