Naglfar is really good live, saw them only once. But it was a nice gig. What do you think about bands as Korpiklaani, Finntroll, Battlelore, etc.
Another one of my favourites is Manowar.
@Zebulon: You know what true metal is. The Polish heroes: Vader. Saw them this year at a festival.
Ever heard of At the Gates. Look for it. ChaosPotHeadNYC will probably like it. To me they are the founders of melodic death metal.

recommendations:
Black: Dark Funeral, Darkthrone, Marduk, Venom, Mayhem, Burzum ...
Death: At The Gates, Napalm Death, Vader, Amon Amarth, Arch Enemy, Children of Bodom, Amorphis, Death, ...
Melodic: Sonata Arctica, HammerFall, DragonForce, Stratovarius ...
Folk: Korpiklaani, Battlelore, Finntroll, Falkenbach, Falchion