I'm certain I'm forgetting some important releases, and also I just like to hear other people's opinions, so you should all comment with your favorites! And if anyone would like to hear an album from my list, let me know and I'll post it.
1. Menace Ruine - In Vulva Infernum AND ALSO Cult of Ruins AND ALSO The Die is Cast
- unique drone and ambient black metal. 3 albums in one year; how prolific!
- awesome anarchist black metal
- very good sludgy metal. Not much black though.
- crossover-style oldschool thrash
- it's Boris.
- anarchist folk music played at a punk tempo
- thrashy death metal that actually makes me enjoy death metal
- instrumental experimental rock/fusion that's actually quite interesting. Also has the best album cover of the year.
- more excellent revolutionary French hip-hop. Not quite as passionate as Entre Ciment et Belle Etoile
- riot ska, short but very good
- very trippy Finnish psy-trance
- really good black thrash; not afraid give a Megadeth style solo
- black metal with very nice use of violin
- interesting addition of hardcore elements to black metal
- neat melodic death metal
- weird japanese folk black metal with a prominent manic, improvised flute
- beautiful, depressive black metal
- gothic doom metal done right.
- acoustic shoegaze/ambient/drone
- African-Canadian hip-hop
EDIT: I have now listened to Torche - Meanderthal (sludge, doom metal), and I think it deserves a spot in my list as well.
EDIT EDIT: Ufomammut, Gojira, Genghis Tron, and probably others I'm not remembering also deserve honorable mention.