This is the deck I use to level up Priest. It has a decent win rate. It averages about 30% wins in casual play. I'm just using it to level up a priest, so this is not a ranked deck. 2 leper gnome 1 shieldbearer 2 mind blast 1 nat pagle 2 novice engineer 1 sunfury protector 1 arcane golem 2 ironfur grizzly 2 jungle panther 2 wolfrider 2 chilwind yeti 1 defender of argus 2 sen'jin shieldmasta 2 holy nova 1 booty bay bodyguard 1 stranglethorn tiger 2 argent commander 1 hogger 1 reckless rocketeer 1 ragnaors the firelord
I built one that I'm using in practice mode with 100% winrate after 31-0. Almost free to build, very efficient as the game AI will more likely go for your taunters or to the face while your lightwell will keep you alive untill your big guys come in. Deck Builder - Hearthstone
One of the perks of playing in rank is that you move towards your golden portrait aswell. XP-wise you get alot more against proper opponents.