Ele is super fun, great damage and survivability, good kiting and flag carrying ability, purging enemies buffs and heals, countering nerds with wind shear and figuring out the best ways to punt (thunderstorm) to disrupt whatever the enemy team is doing.
Mage is fun too, though a bit more squishy I think. Piloted by the right person can be a huge offensive advantage however, just ask yowza.