For an album that rocks in a completely unexpected way, check out Zdzisław Piernik and Piotr Zabrodzki - Namanga ...
http://www.badongo.com/file/10279972
It's jazz, classical music, electroacousic improvisation, and chamber music rehearsal.... but somehow it fucking rocks too.
Also, Hairdryer Peace by the Hospitals rocks as well, but it's a very unfriendly kind of rock.
Also.. duh... Boris - Smile!
If you want to dig back a few more years, listen to Coachwhips and Number Girl. I always reccomend them to those looking to rock.