Two of my favorites are Johnny Paycheck's "TAKE THIS JOB AND SHOVE IT" or John Lee Hooker's "I'M MAD"? Big Bill Broonzy's "WHEN WILL I GET TO BE CALLED A MAN?", "GET BACK" [=BLACK BROWN AND WHITE] and "PLOW HAND BLUES" would certainly qualify. "STRANGE FRUIT" is about as pissed off as you can get.