Hmm.. what class to choose?

[AceTravis]

I'm very indecisive about what class to choose. I want to play a class I enjoy but I also want to be competitive when it comes to PvP. I'm interested in playing a necromancer, SK, or wizard. I've noticed on the pvp leaderboards that wizards, monks, and rogues do really well while, surprisingly, necromancers and SKs are doing poorly(or there just isn't that many of them). I always remember necromancers and SKs destroying PvP during classic but maybe I'm greatly mistaken. Any suggestions or insight would be greatly appreciated.