Burzum is depressive and not positive metal.
I second these along with Ensiferum.If you want to hear some of the most catchy and upbeat melodies ever, check out Equilibrium. Their new album Sagas was just released, and it's fucking gloriously epic as hell.
Turisas (check out the song "To Holmgard and Beyond" on youtube)
Defiantly, eh?
btw Einherjar did you hear the ZZ Top riff on track 6 on the new Equilibrium?