Hearthpwn

I've been having a lot of fun with variations on this deck since Whispers of the Old Gods released.

This is what the deck has evolved into after 40 odd games going from Rank 8 down to 10 then back up to 6, I'm sure that it's far from done but to me it feels closer to the old Miracle Rogue decks than any other that I've played since the Gadgetzan Auctioneer nerf. 

Basically you're looking for the the Emperor Thaurissan, Malygos, Sinister Strike combo. 

Yogg-Saron, Hope's End is only there as a last resort Hail Mary, if everything else has gone wrong. Never use him from a position of strength, he's just too unreliable. Perhaps surprisingly, when you use him in the right way he'll get you out of trouble more often than you might think he would.

Something else to note about this deck is the complete disregard for the Rogue hero power. Since the Blade Flurry nerf and the loss of Antique Healbot and Tinker's Sharpsword Oil from Standard play, in my opinion the Rogue hero power just isn't worth the bother, If you can play Sir Finley Mrrgglton early, do so, otherwise with all of the low cost spells, extra coins and careful planning you shouldn't really have extra mana to spend on your hero power anyway.

One of the biggest strengths of this deck is its versatility, cards like Journey Below, Undercity Huckster, Edwin VanCleef and Shifter Zerus allow you to adjust on the fly while also fitting into the overall archetype nicely.

One last note that's pretty obvious really, if you're playing against a C'Thun deck do not use your Big Game Hunter on anything other than C'Thun himself. You should be able to deal with everything else by minion trading and careful use of damage spells and Sap but in this deck, BGH and Yogg are the only real answers to the big guy himself (and we've already talked about the unreliability of Yogg).

Update (30/04/16):

So, as the meta settles in a bit more I've been seeing a lot more aggro and zoo. The lack of board clears in this deck was starting to hurt a bit too much so I've put in 2 x Doomsayer. Use him early to regain tempo from Zoolock or Aggro Shaman, use him later against Druid or Warrior to absorb 7 damage that would have otherwise gone to your face (sometimes the Fadeleaf Toxin dream combo will allow you to clear a board that you'd have no business clearing otherwise).

Also I've added in 2 x Unearthed Raptor. There are plenty of deathrattle effects in this deck to copy but even if you have to drop it on an empty board on turn three the body means that you'll still maintain tempo.

Out go Shifter Zerus, Edwin VanCleef, 1 x Undercity Huckster and the SI:7 Agent. Basically all of these cards are only conditionally good not always good, the deck needed more stability to survive an early game onslaught.