Well, it's not quite over, but I will edit if anything changes between now and the end of the poll. However, the result almost certainly will not change.
Iron Maiden's The Number of the Beast won with 10 votes. Now, I am a huge fan of Iron Maiden, but this is not even close to my favorite album from the iconic band. I much prefer Seventh Son of a Seventh Son, Powerslave, and Piece of Mind. Actually, I find the title track to be somewhat overrated. I do enjoy other tracks off of it, but again, not as much as some of their other albums.
Venom's Welcome to Hell placed second with two votes. This is a fantastic album and a huge influence on the thrash, death, and black metal genres. The "other" category also had two votes with a commenter stating his preference for Sweet Savage. That is not an album I am terribly familiar with, but I will definitely check out. The other vote went to Angel Witch's self-titled album, and I agree quite well with this. The title track is a great song, and one of my favorites from the NWOBHM scene.
I was not shocked that the Raven album did not receive a vote, and the Blitzkrieg album is pretty much underground, except for the song "Blitzkrieg" which was covered by Metallica. However, I was shocked that Diamond Head did not gain a single vote.
My pick from these possibilities is the Diamond Head album. There are so many great songs off of it that are infectious as hell and generally a lot of fun. I am very surprised to see it not get a single vote.