Malygos Druid is the strongest Druid deck in the current META, this is the best list for season 32, Nov 2016. There are a few tech choices you can switch around, but with the Shaman on the ladder right now Baron Geddon is the best 7-cost drop. The 2 damage per turn wipes out the totems and it contents a strong Thunderbluff turn.
Mulligan hard for as much ramp as you can find. The sooner you can drop some big minions to claim the board the better your chances of winning. Don’t forget to Nourish and cycle when you can too, lowering the cost of Arcane Giants as fast as possible is also important.