It has to be W.A.S.P. in my books but Twisted Sister only miss out by in inch!
I hate choosing favourite bands and as a general rule, try to stay away from it. Honestly dude, I need to get a regular fix of most the 80's metal greats.
If W.A.S.P. doesn't have Chris Holmes in the band, it's a tough call. I've seen them twice live, both with him in the band and he was so drunk that he fucked up all the leads.