First, my two front runners for AOTY thus far go to:
Deathspell Omega - The Furnaces of Palingenesia
If you don't know DsO you might be in for a bit of a shock, as they are both 'avantgarde' and 'dissonant' while being black metal. This might be one of their most accessible albums as it has pretty good riffs that are hooky enough to keep your attention throughough, but DsO can best be described as controlled chaos. I don't like a lot of dissonant extreme metal but somehow they use it in a way that is still very beautiful and not off-putting.
Deus Mortem - Kosmocide
Again a black metal album, but this one is very different than the former. It is semi-melodic, the drums are fantastic and the riffs and solos are great. Production is good for BM as M from MGLA did it.
Onto more friendly metal appealing to a wider audience...
Tanith - In Another Time
This is more friendly to more audiophiles as it isn't heavy, has dueling guitars (Satan's guitarist is one), both a seduction female and a clean singing male vocalist. Kinds sounds like Wishbone Ash to me. DR rating is pretty high, production is good.
Dreadnought - Emergence
Billed as progressive metal, which is it but borrows on some metalcore, some doom and a bunch of other stuff. Not usually my thing but it definitely works well. Female vocals, both clean and harsh.
Plenty of other good stuff this year, but this is a little of my fave plus great stuff that a wider audience might enjoy.