aic,TooL,nirvana,hole,pantera,mars volta,cult of luna,system of a down, acid bath,slayer,crisis,ministry,godflesh,soundgarden,sabbath,doors,lamb of god, opeth,....thats all i can think of
mostly g-funk. (g-funk is the topics mentioned in gangsta rap but not aggressive and it is put to relaxing music) e.g - 2pac 'changes' or coolio 'gangstas paradise'. when lifting weights at the gym i listen to heavy metal or gangsta rap. anything from the following: 2pac the outlawz notorious BIG jedi mind tricks wu tang clan