Again and again you keep rolling ur stupid line of "UHH DKS WERE OP AT THE START" which still is meaningless, the question here clearly was "on WARMANE" and warmane never had a pre 3.3.5a (to my knowledge) based wotlk server (talent wise) so what you are on and on about is totally meaningless.
Stop wasting everyones time and every thread crying about DKs. They may have been the best overall wrath class but every single question about what is best since 2011 has been about season 8 since the only way you can play wrath is on private servers and i think almost all of them run 3.3.5a.
And /thread, the question was what class, not what race. And yes human > all but its fairly irrelevant. Due to how the game works one side will always dominate the other in pvp since people go to where the players are.
Now to answer the question, paladins are the best class, they are insane in bgs (holy/ret) in 2s (holy, war/Pal being the best comp), 3s (holy), they are viable in open world pvp, they do well in pve and all have a fairly low skillfloor. What is the best spec i would answer differently, id say shadow priest since they are also good everywhere and vs pretty much everything. They are good in bgs, good in duels, good in arenas and are all around very flexible without having to juggle gear so much (a ret is **** in duels vs a lot unless he gears specifically for that). While they arent as asmazing at specific things like some paladin specs (or arms wars in 2s, or DKs in duels) they do everything well.