Amon Amarth (Cry of the Black Birds, With Oden..., Twilight of the Thunder God)
Entombed (the fast ones, Year One Now, About to Die, etc)
Cannibal Corpse (the slower tunes in this case... eg. Death Walking Terror)
Black Label Society (the slow chuggy ones, Counterfeit God, Superterrorizer, etc)
Vader (Wings, Cold Demons, etc)
Halford (Made In Hell, Drive, etc)
Sonic Mayhem (the faster breakbeats from Quake III soundtrack)
E:
When doing weightlifting and such. For running, I just play random stuff, although lots of energetic industrial/EBM works the best. For slow walks in the darkness, nothing beats black metal (Darkspace, Kataxu, Mayhem, older Emperor, etc, darker moody ones), and otherwise dark feel/graveyard music like Tony Martin era Black Sabbath and The Amenta's album n0n.