i went to Venom's big Hammersmith show in (i think) 1984 or 1985 and they were very loud, but the overrding memory was the bloody flame jets, didn't quite sear the eyebrows off but not far short! APD tour at Hammersmith was loud, as was front row stage left on the Saturday 10th anniversary show. Michael Monroe is the loudest act i ever saw at the Camden Forum (aka Town and Country Club as was)
I've orderd some of the plugs recommended on here as taking the wife to Paris with me