I have several I'd like to see. TAD, Fudge Tunnel, Mr. Bungle, Fugazi, The Apex Theory, Priestbird, City of Caterpillar, Frodus, Big Black, Husker Du was mentioned already...
Also Kyuss with Josh Homme but that will never happen now. We are stuck with Vista Chino. I would also be down for Them Crooked Vultures.
The Jesus Lizard reunion tour was so damn awesome I wish they would have stuck around!
70's occult glam band White Witch would be a treat.
I'm not sure if they are broken up or not but Harvey Milk has not toured or made any music since 2010 so I'd like to see them come back and make some noise.
How about Henry Rollins? Rollins band? Black Flag? I'd like to see him onstage again not telling stories or interviewing Dino Jr.