Official:
Melvins: Houdini Live - 7 minute rendition of Night Goat, albeit 2 and a half minutes of arabiental intro, while Hag Me reigns supreme, absolutely mammoth sound. Pearl Borab clearly wasn't meant to be a live song so they changed it to make do, pretty awesome job was made of it to be the album opener.
Black Sabbath: Live at Last - Really good, thoroughly enjoyable with many of the Sabbath classics.
Unofficial:
Electric Wizard: Roadburn 2005 - Supercoven, Return Trip, We Live, Dopethrone and Eko Eko Azarak. Brilliant set, for fans of the Wizard and owners of some great speakers, you will love this.
Sleep: Live Noveraber 9, 1991 - Not the best sound quality and the studio versions will probably still be preferential, but no doubt this would have been amazing to be at.