I've been getting into NWOBHM for quite a long time. It has like 200+ bands that came out from that era in the UK from 1979-1984. Alot of these bands had a punk-meets-metal flavor that really helped influence trash/death/black metal bands in the 80's. It sucks that only a few made it far. These bands truly had the potential but it was the mainstream acts that kept them from becoming successful.
My favorite bands are Angel Witch, Cloven Hoof, Iron Maiden (Self-titled & Killers albums only), Def Leppard (On Through The Night & High 'n' Dry albums only), Tygers of Pan Tang, Diamond Head, Venom, Grim Reaper, Atomkraft, Blitzkrieg, Holocaust, Legend, Persian Risk, Saxon, Satan, Demon, Witchfynde, Witchfinder General, Pagan Altar, Tredegar, A II Z, Sweet Savage, etc. and the list goes on my faves.
PS: Anyone thinking that the songs "Am I Evil" or "The Prince" were originally recorded by Metallica, then they're posers who don't know their own "favorite" band too well. Those songs were beautifully written by the members of Diamond Head, and seeing as Metallica grew up loving these guys and citing them as influences (not like every Metallica fan cares, amirite?), they turned to cover and screw up those songs.