A good friend of mine is a top session vocalist in LA. He almost got the gig to play with Van Halen after David Lee Roth left. Anyway, he has a monster voice and can scream like no other. He told me that many of times, he would simply use an SM57. Sometimes clinets would put the SM57 in in the control room and have him sing with the speakers blasting for that live rock-n-roll feel. Not a technique I would use, but none the less... So I would agree with the previous posts: SM7 or SM57.
