PatzCU said:
Seconded. I wouldn't play a Shaman for caster DPS, it's been pretty weak since Cataclysm came out. You should be safe with Mage, Druid, Priest or Warlock though.
I still think Elemental Shaman have some of the best spells in the game, especially going back as a Warcraft 3 player and being introduced to Thrall in your first mission there. Chain Lightning? Hell yeah. And getting guaranteed critical strikes with Lava Bolt is always fun (disappointing that you get such an important spell for the class so late.) Bloodlust is always fun to have too, though with mages having it now, it's not as special. The only thing I dislike is that I still think totems are a weak mechanic and could be further improved. They're really just not that fun as is.
But anyway, just to further clarify, hybrid classes were originally intended to be slightly worse at dps than pures (mages, hunters, warlocks, rogues), but in the current design, that's not necessarily true at all. Mages are fun, Warlocks are similar but with a demon pet, though I've learned that I'm not a huge fan of pet classes after leveling a hunter, Priests can be pretty powerful as Shadow, but you should be prepared to heal a lot as well, unfortunate as it may ber, since they have two healing specs and healers are going to be in greater demand than dps more often than not.
For a player who is not sure what they would like to do, you can't go wrong with Druids as they cover every role in the game - Ranged DPS, Melee DPS, Tanking, and Healing. You can try out anything you want if you ever decide you want a change rather than having to level another character. You'll spend most of your time shape-shifted though for 3 of those roles (RIP Tree at all times) so if you don't enjoy looking like a bear/cat/owl and/or like to see your armor in battle, that may be something to consider.
Nothing wrong with Mages though, they're great if that's what you're into.