I love offensive magic :) And I love the forest elves :) Therefore, I'll vote for those whose invaluable magic helped me eliminate stacks of bloodthirsty neutrals, namely dryads and high druids (the ones with the deer :)), whose swarm of bees and lightning spells saved the day in many battles. Well, you can also mention the mages with their fireballs (I've read a lot about the Watchers), they are also good :) Shamans have to sacrifice goblins, but with their initiative, by the time they get to the chain lightning, they'll be dealt with without it. Higher levels are more valuable with Light and Darkness magic, because with their quantity, the relative effectiveness of the spell decreases. Well, that's my opinion on this matter, don't judge me too harshly :)