Hunter: Reynad's Mad Hunter
The scourge of the ladder once again. Rexxar is everywhere from rank 20 to Legendary, and it's partly thanks to Reynad 's new build, which combines the old Midrange Hunter along with more recent Secrets/Bow builds. Between the efficient Beasts that Naxxramas introduced, allowing Hunter to use Houndmaster on less, well, shitty beasts, and the absolutely broken mechanics of Mad Scientist, you have a hyper-efficient monster of a deck. Reynad runs Leeroy for extra burst, and even though Timber Wolf is no longer present in the deck those Whelps can help boost your Unleash The Hounds.
The Hunter's hero power means the class naturally has a clock on you. In my opinion it's one of the best in constructed because it offers the most bang for your buck, outside of Lifetap of course. In conjunction with aggressive decks, Hunter dominance has produced some of the least fun metagames to play in. This deck definitely isn't in pure aggro aggressive—in fact for a midrange deck it's actually really light on minions. But all of its creatures are efficient, and it has so much draw power in that you can reliably see most of your deck in every game, something that is a massive advantage if you know how to use it.
Play it because… You want to climb the ladder fast and don't care about the haters.
Paladin: Backspace Paladin
Backspace , creator of the notorious Aggro Rogue deck of the same name, brings us another creation—and this one is far less rage-inducing. Overall, the deck is really similar to older builds of Control Paladin. The difference is that it now actually has something to do before turn 4. There's far more early game here, including a pair of Zombie Chows and Harvest Golems to prevent more aggressive opponents from snowballing the Paladin out of the game. Further up the curve it features a pair of Sludge Belchers, plus all the major midgame Legendaries.
In fact, one thing that I noticed about this deck is how much smoother the curve looked compared to older Paladin lists. While working on my own build pre-Naxx, I found it quite a challenge to stop the deck from having overloaded mana slots, yet here it all flows together. This deck really only get's started on turn six, though. It's unlikely to ever win fast, but between Tirion, the silence magnets that are Sylvanas/Cairne, plus the safety net of Lay on Hands, this Paladin is well poised to come out on top in the long run. Which has always been the class's strength.
Play it because… Pure control decks can actually be some of the most satisfying to play. Big comebacks make you feel like you really earned the win.
Warrior: Naxx Control Warrior
Speaking of control, ever since its OTK got nerfed, Warrior has almost exclusively been a control class. So how does it fare in the slower post Naxx meta? Pretty well. This particular build, by Impact, is similar to the pre-Naxx Control Warrior builds, but more efficient in certain slots. It still runs a massive assortment of Legendaries, but nowadays it seems like every deck has at least 2 or 3 of the midgame Legendaries. The one that stands out is Ragnaros, but in this slower environment, the Firelord can actually shine. With card slots so constrained, almost no deck is currently running BGH, which has traditionally been Rag's worst nightmare.
Outside of that, the deck has a pair of Sludge Belchers and Sen'jins in favor of the Azure Drakes and Kor'Kron it used to include, once again highlighting the slower, more control-oriented environment. Some of the card choices seem a bit outdated to me (Running Gorehowl in such a Harrison-heavy meta), but overall this is likely to be the Control deck of choice for the foreseeable future. Especially thanks to it's solid match-up against the aggressive Mad Scientist plus Undertaker-style Hunter builds.
Play it because… Thanks to Cards like Unstable Ghoul, Death's Bite and Sludge Belcher, the transition between early and midgame is now much more stable. Along with the surfeit of removal spells, these new Warriors are one of the best counters for the plague of Hunters.
Well, that's all folks. Hopefully this look at some of the decks that constitute the post-Naxx meta have inspired you to try them out for your self, or even make something of your own. Happy hunting. (You're just going to play Hunter, aren't you?)