I know you said no Pantera, but if you haven't heard Cowboys from Hell, you should check that out. It's a completely different sound from all of pantera's later stuff. You might wanna check out some old Sepultura, specifically the Schizophrenia, Beneath the Remains, and Arise albums. Everything after that is a lot less "thrashy" and heavier and more hardcore sounding. Might also want to check out some of the german thrash metal bands, like Sodom, Destruction, or Kreator.
If you want to hear bands that sound like St. Anger, check out Slipknot, since that's who Metallica was trying to rip off when they made that album.
Also, I don't know if anybody has said it, but Dragonforce is an amazing speed/power metal band. They really transcend the genre of metal and are just in a category of their own--the awesome category. I have friends that hate metal that love Dragonforce because they're just crazy good.