What is the preferred choice for 80-90? My gear is here for you to see if that makes any difference. Haven't done much with this mage since WotLK, not familiar with the differences and all that jazz.
Frost is always the most secure spec. Fire is the most fun (Dragon's Breath is only a 20 second cooldown, so AoE your heart out), IMO. Arcane is cool at low levels (60 and under), but lackluster at higher levels.