Hearthpwn

I've been playing this deck for several months now (with a few modifications) and it's my best deck with a solid win-rate on ladder. The essence of it is to build up sturdy bodies on the board to trade effectively. The various mind controls (Shadow Madness, Cabal Shadow Priest, Shadow Word: Pain, all of which combo well with Shrinkmeister) help to stop the enemy swamping the board with small minions, big threats can often be taken out by brute force, but there are also some good removals (Shadow Word: Death, Lightbomb, Mind Control).

The deck is most fragile in the early stages - you need to build up board presence, otherwise you can be killed off too quickly. But you can win against face hunter and other aggro decks if you get okay cards and if you focus on clearing the board and healing yourself. Try to save your Holy Nova and Lightbomb for later in the game when the opponent pulls out a ton of minions (the latter card is especially good to clear out the inevitable Dr. Boom).

In principle, whenever you can take something out with a minion without losing it, do so. Try to kill off any card-drawing minions to strangle the opponent's card flow. If you're up against an aggro deck, don't be afraid to useShadow Word: Death on the first 5-attack minion if it means you don't have to trade. Against other decks, keep it for some big minion/legendary.

The heavy mech presence in the deck is mainly to make good use of the amazing +4 heatlh battlecry of Upgraded Repair Bot (but don't be afraid to put them on the board if necessary even withotu using the battlecry). Shadowboxer has won me the game on several occasions against aggro decks, esp. if you can boost his health so that he survives multiple turns. Sneed's Old Shredder is nice because it's a mech and it's very sturdy, but you could swap it out for some other strong legendary.

I used to run a second Light of the Naaru and an Injured Blademaster, but I swapped them out for two-times Shadow Madness to help deal with aggro decks and large boards. If at all possible, use them two take out two enemy minions at once, or to open up a dangerous minion hiding behind a taunt.

Mulligan for your 1- and 2-mana minions, if you have some, then also keep Power Word: Shield, Light of the Naaru and Shadow Word: Pain. Keep Dark Cultist if you don't have a lower-mana minion.

If you try it out, let me know how it works for you and what troubles you have. Hope you enjoy it!