PvE -> Fire Rage
PvP -> Eye of Flame
It's always ever the fire one cause more damage output, though since my MagSorc has Shock buffs I use the shock one. Dunno if I'll use the Frost one on my Warden since she's an Ice Mage, I'll have to see what it's like over using Permafrost, cause that Ult increases my max magic.