Plenty of good choices on here, some bands I love but couldn't vote for them as the best duo. I got it down to Hanneman & King and Kisser & Cavalera, and went with the Sepultura guys. I just feel like some of the stuff they did early on was incredible, and some of my favorite thrash material.
6/21-Full of Hell/Seven Sisters of Sleep
7/27-Something Bloody Metal Fest