What class/race combo should i play with in Cataclysm?

Since Caty my attention span with characters has been going down a lot. I've literally played every class already. But since I have more than 1 class that I enjoy, I will be playing one and feel like the other is best... it's almost like a guilt trip :P I do very well with Warlocks, Shamans, Druids, and Rogues. If someone could give advice on on these and make me swing towards one or the other, because I get stuck in the 40-50 lvl range so I actually have characters of each class in that range so it wont be that bad like starting over from lvl 1. I'm on the Horde. I already have a 85 Mage and 85 DK (got them to 80 in WotLK and took time getting them to 85 once i got Caty) and i just get bored with them now. But i do PvP with them sometimes. I'm a PvP person, so I guess factor that into your advice for classes. I also want to go as far as saying that race has an impact on my choice too. Before Caty i would never do a tauren druid but now i would play a tauren. On the Horde, idk why, but i dont concentrate well with Orcs, Undead, and Goblins (sorry to those who play horde and Orcs, Undead, and Goblins who answer this) Undead actually used to be my favorite but for some reason i dont like it anymore. I dont use heirlooms because i like the challenge i get by starting like everyone did in vanilla and BC, but if you think I should use them then just say so and ill just do dungeons and get Justice Points for them. so if anyone can give a helping hand with this, it is deeply appreciated.