Awesome Libertarian-themed techno (on the few vocals that are found) in
Boards of Canada - "One very important thought", and "Trillions"
The Sex Pistols - "Anarchy in the UK" Johnny Rotten has attended a few Libertarian Conventions before, and commented on Ron Paul when he played Leno

...
P.I.L - "the order of death"
FEAR - "foreign policy", camarillo, etc... very libertarian, and their drummer does the taxes for tons of musicians, and is anti-IRS, and very anti-state
A lot of things on the Beatnuts' first album "street level" (hip hop)
great instrumentals:
http://www.xplodingplastix.com Amon Tobin -Chomp Samba / "Keeping it Steel"
NoFX - The idiot son of an Asshole (about GWB)
Most of the songs off of the latest Firewater album "the golden hour" (and yeah, I know the guy rails against the capitalists too, but not overtly, even if he is an "anarcho-syndicalist" or something similar. He seems more "libertarian-left" every record he records, and his earlier stuff with Cop Shoot Cop is also legendary... "Traitor/Martyr" and "Lies")
Ministry "Lies, Lies, Lies"
The Plasmatics - "Concrete Shoes"
Black Flag - "Police Story"
Ministry - "NWO"
Joy Division - "They Walked in Line"
Soundgarden - "Hands All Over"
Tenderloin - "ABC"
Primus - "Sathington Willoughby"
The Reverend Horton Heat - Bales of Cocaine, Marijuana, Bullet, Blue Sky, 5-0 ford, yeah right, etc... All libertarian-themed, pro freedom, pro-american, etc... None overtly political, because the Rev said something like... "politics is bullshit, and we avoid it"
Fear Factory -Remanufactured (the whole album is anti-state, and anti-fascist)
Bad Religion is often libertarian themed like their song "A Walk"
Circle Jerks -Coup d'Etat, and others
Ice-T, of course
to some extent "Rage Against the Machine", although they are economics-wise stuck in about the third grade, they probably qualify as "libertines" or social libertarians, along with Jello Biafra and the DK
Cypress Hill is fairly libertarian, and not wusses, like DK are...
And then there's this dark corner of society (outlaw, sociopath, violent rebel, criminal, slimebag, and all around "terrorist" LOL...):
http://www.youtube.com/watch?v=I2fgTky_L_0And for the artilect rebellion:
Squarepusher "I wish you could talk"