take the shaman and combine it with hunter/warlock, you will trash anything and even have a pet who can tank

Goto wowiki for easy to start macros, i dare say hunters/shamans have the best "one button" macros for dps

Tho any combination would be fun but personaly I never liked mage even if i did lvl one to 60 pre tbc

If you only plan to play 2 accounts even melee is viable