Music from 2012:
All Hail The Void by Enabler MKE
Speechless

Fast, hard, dirty crust punk/metal. Way more groove than anything else I've heard this year. I know the band members and this album was featured in Spin Magazine. Check out last year's "Year One" which is even dirtier.
Cancer by Showbread
You Will Not Die In A Prison

No one song can represent this album, but the whole thing is
free so that's fine

Musically it's "raw rock" with lyrics all over the place. It's not nearly as well written/disturbing as "Who Can Know It?" so download that one too.
All Creatures by ElisaRay
Foxden

Guitar and violin folk with smooth vocals from male and female singers. Good lyrics, fall asleep to this one. This album is
free.
Impulse OST by Meteo Xavier/12 Followers
When You Find A Stranger In The Alps

Experimental, generally awesome electronic music. Chip instruments, synth, and real instruments all thrown in a skillet. This album is also
free.
Wounded Healer by The Followers
Wounded Healer

Slower, darker folk-rock worship with electric guitars. Eclectic and super catchy.
Glory Outshines Doom by Slang
もの言わぬ本 / ろうそくのまち

Super heavy metallic hardcore, in Japanese. Pretty hilarious, but there's a serious message. Watch the video!
Wandering by Yosi Horikawa
Bubbles

Noise art with samples collected from around Japan.
Blueshift by Protodome
Oh I Feel Just Fine...Because I'm Making Macaroni

The final "Blue" album is the best. It's happy chiptune acid jazz and this time it has vocals! Snag it for $1.50! The macaroni recipe is included in the download.
Falling Apart by LukHash
Pixelove

You can't resist a new Lukhash album. They're all on his website. Chiptune/synth music and this time around there's some dubstep elements thrown in. Download Digital Memories, too.
Katawa Shoujo Enigmatic Box of Sound
http://1.bp.blogspot.com/-1mDNFBQ6O9Q/UBIIOPG-XeI/AAAAAAAACEA/0irtleQS0FQ/s1600/Katawa+Shoujo+Enigmatic+Box+of+Sound+(by+Nicol+Armarfi,+Blue123,+Juno).jpg
Collaborative soundtrack for the visual novel which hopefully needs no introduction.
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Other music I listened to this year and feel like mentioning:
In Due Time by Next In Line (punk rock)
free
Physical Graffiti - Led Zeppelin
Deep Purple
Valkyrie Profile OST
Veil of Remembrance by Crimson Moonlight (Black metal)
Frederic Chopin (classical piano)
Once I Was a Bird by Lauren Shera (slow female-led folk)
free
Master of Puppets by Mettalica
Mirror's Edge OST by Lisa Miskovsky
Xenoblade OST
Abbey Road by The Beatles
Hydorah Arranged Tracks (various genres)
free
Stab At Love EP by The Shiny Darks (punk)
free
Steins;Gate OST
Thunderforge by Skyforger (heavy viking metal)
Hymns From The Blazing Flesh - Stairs to Nowhere (WTF)
free
Neurovision by Mitsuo Suzuki (Electronic)
Lesser Men by Abel (indie rock, great concept album)
free
The work of Thor Bremer (experimental/neoclassical/jazz)
Anti-Meridian by Brave Saint Saturn (groovy rock)
Quill by The Last Bison (?)
free
The Healing of Harms by Fireflight (hard rock)
The Raven And The Reaping by The Famine (metal)
Infinite Titanic Immortal by A Hill To Die Upon (metal)
Art Ambidextrious S/T - poetry/rap
free
Burial by Extol (Absolute classic death metal)
Bridge Over Troubled Water by Simon and Garfunkel
At The Dawn of War and A Forlorn Throne by Sletchvalk (Viking metal)
Dance Or Die by Family Force Five (Goofy dance/rock)
Ensiferum - S/T and From Afar (Viking metal)
Down The Way by Angus and Julia Stone (soft rock)
Dimensions by Believer (Thrash)
Emotional Cues - Eiko Ishiwata (Orchestral)
free
Fight With Tools - Flobots (Political radio rap)