I don't really think there is a "best" class for pvp.
I do think that rogue is the best pvp class when you are 1v1 and can initiate the the fight, i.e. stealth.
It is really enjoyable to stealth up to a target, that has no idea your there. You open with cheap shot, sinister strike, sinister strike, gouge, sinister strike, eviserate. Before they can react they are below half life.
I can't wait to get kindney shot.
Good luck to you!