Hearthpwn

I originally made this for Old Gods, but the C'Thun combo still works in this meta. You can replace 0, 1, 8, 9 mana cards with the best cards you have. The rest you should keep as is.

Overview

The logic behind this deck is simple. Only include the cards you want to see at each mana level and fill the rest of the deck with 0-mana and 1-mana drops.

Clockwork allows you to get rid of the RNG associated with card draw. The key to this Tavern Brawl is to limit your deck to the specific cards that you want to draw at each mana level. We do this by only including 1 or 2 of each card at important mana levels and dumping a bunch of unimportant cards in less important mana levels. 

History

Here is a cheaper version that can be tailored to your card set:

http://www.hearthpwn.com/decks/584091-cheap-f2p-clockwork-cthun-win.

Mulligan Guide

Mulligan for Innervate and 0-mana cards. If you have Innervate or the coin, take 1-mana cards. Most of the time you will know every card you are going to play before the first round. 

Strategy

Very simple.  Play the card that you draw each turn. Try to maintain board control. Use the 0-mana drops and the coin or Innervate to play the 1-mana drops in order to clear the board and stay alive. At turn four, when your taunts come out, you can do face damage and let your opponent exchange minions. 

It is the same drops every game. Play smart and maintain board control. 

Other Replacements

0-mana - Add in 0-mana cards if you are low on 8-9-mana cards.

8-9-mana - Add in any Epics or Legendary cards that you have in your collection. The more cards you can add in this mana level, the better. It will allow you to play high level drops if you don't get a C'thun kill. 8-mana drops are the best because they allow you to use your hero power as well.

2, 3, 4, 6, 7, 10 should not change. There should be no other cards with those mana values.

4's and 5's can be changed out if you don't have the cards, but you need something strong. 

7's can be altered a bit too, but the taunt at 7 is important. You can also throw in Bog Creepers if you don't have Twin Emperor Vek'lor.

Edit 1:

Added in two Volcanic Lumberers and dropped the Majordomo Executus and Nefarian. 

Edit 2:

I tried adding a Brann Bronzebeard to match with C'thun, but I drew it on three and it screwed up the flow of the deck. 

Edit 3:

Updated for Gadgetzan. Still works very well.