This makes me sad.

Immortal Technique for sure.
Kendrick Lamar also never ceases to amaze me.

what tattoo to get next?

Canibus

Chiddy Bang and Kid Cudi

Chiddy Bang are entertaining but I would in no way describe them as thought provoking.

True. I actually find it more thought provoking musically then lyrically, so your right. Doesn't really fit the topic. But it still is thought provoking for me ha.

aesop rock

Sweet ideas. I am pretty into Sage Francis' lyrics lately - his new album has him practically singing and playing guitar but still manages to stick to a sick flow.

my favourite one today:

civil disobedience (I can't post the url til I've posted moar aha)

Jedi Mind Tricks

I don't disagree with any previous answer up there. Excuse me if I repeat yours, it's just easier to think that way.

El-P
Aesop Rock
Gift of Gab
Illogic
Panacea
Del the Funky Homosapien / Hiero Crew
Myka 9/Aceyalone/Abstract Rude (Freestyle Fellowship//Haiku D'Etat)
Living Legends
Anticon
Oldominion
Antipop Consortium

Provoking thoughts of terror and violence, maybe!

Hatred and Distrust, they breed.

Some decent beats, but the message and style doesn't work for me.

I don't mind it, I like a lot of it in fact. But thought provoking just isn't what comes to mind.

Gotta say Wayne. As much as people hate on him and I understand it... he's a puppet, a product, a gimmick whatever and it's all just about money blah blah, he's still got those one liners that just make you stop and think, Hey... did he really just say that ****?