Hi Naoli! I'm new too, it's great to find other people who love metal!
I prefer Pantera and Fear Factory, they just really keep me going. Something about Burton C. Bell's voice that just...makes me want to run, I guess. hehe.
ButI've also found Killswitch Engage, Hellyeah, some Korn, Sepultura and Ozzy are GREAT workout partners!
How about yourself?
"My favorite time is now because now no one tries to tie me to a stake and make barbecued Simi. I did not like them people from long ago cause they would look at me and scream, then try to exorcise me. Exercising is good if you are Richard Simmons, but it is not good if you are the Simi. They did not like the Simi, so the Simi did not like them." - Simi from DH Website