Adding more albums could encourage voting for different ones, but it might not result in that anyways. I've mostly been voting for the same four albums over and over because I don't think the others on the list are as good as those (or, at the very least, know that they will make the list without my help). Limiting absolute number of votes for a given album probably will slow things to the point of boredom, unless maybe the +2's are limited so that someone +1-ing a certain album can always be counteracted. But I really don't care that much and enjoy the arguments that result more than the sanctity of the list, so whatever.
1. Atheist - Unquestionable Presence: 36
2. Black Sabbath - Master of Reality: 20
3. Candlemass - Epicus Doomicus Metallicus: 33
4. Coroner - No More Color: 26
5. Deathspell Omega - Fas, Ite, Maledicti, in Ignem Aeternum: 29
6. Demigod - Slumber of Sullen Eyes: 26
7. Demilich - Nespithe: 15
8. Deströyer 666 - Phoenix Rising: 38
9. Enslaved - Vikingligr Veldi: 4
10. Fates Warning - The Spectre Within: 26
11. Immolation - Dawn of Possession: 9
12. Iron Maiden- Seventh Son of a Seventh Son: 6
13. Mayhem - De Mysteriis Dom Sathanas: 38
14. Mercyful Fate - Don't Break the Oath: 32
15. Motörhead - Overkill: 3
16. Negură Bunget - OM: 21
17. Neurosis - Through Silver in Blood: 13
18. Opeth - Morningrise: 31
19. Pestilence - Consuming Impulse: 20
20. Sepultura - Beneath the Remains: 29
Epicus Doomicus Metallicus/The Spectre Within/Beneath the Remains
damn all you black sabbath fanboys... original doesn't mean best
Opeth doesn't even mean good.