So, I can't connect to the PS! server, so I figured I'll give some input on my DH.
DH #1: Cofagrigus
Despite the name of my alt (Mega Rango), Cofagrigus was actually the first DH I chose. There's a very simple reason for this;
fighting spam. But, everybody goes oh by Mega Lopunny don't care about ghosts. Well, that's why
Mummy is so useful. Lopunny gets 1 hit in and is immediately forced out. That can give me time to Pain Split the recovery, spread burns with WoW, lay down T-Spikes, etc..
http://replay.pokemonshowdown.com/uu-192470986
This battle showcases exactly what I'm talking about. Lopunny could very easily sweep my team (and it can if I sac Cof way too early). But, Cof is such a hard counter to Lop, it's not funny.
252 Atk Lopunny High Jump Kick vs. 248 HP / 252+ Def Cofagrigus: 121-144 (37.9 - 45.1%) -- guaranteed 3HKO after Leftovers recovery
I think it's key to note that even Mega Gallade can struggle with Cofagrigus.
+2 252 Atk Gallade Knock Off (97.5 BP) vs. 248 HP / 252+ Def Cofagrigus: 280-330 (87.7 - 103.4%) -- 25% chance to OHKO
At that point, he can spread burn, hit him with a SE Shadow Ball, Pain Split back to full health.
Cofagrigus has definitely pulled its weight throughout the whole laddering experience thus far. But, one of the key attributes is the spread of status. Burn and Poison through Toxic Spikes has nabbed me so many KOs, it's very helpful.
DH# 2: Quagsire
I think everybody has an idea of what Quagsire does. It stares at you blankly while you try to boost and ignores all stat boosts. He is definitely an underrated mon. I ran a Physical Defense set with Curse. It's not so much a sweeper (trust me, I've had Toxic ruin in so quickly), but more of a check to physical boosters like DD/Coil Zygarde, SD Lucario, Hone Claws Mega Aero, PuP Mega Lopunny, SD Mega Gallade (needs to watch out for Leaf Blade, but I think most people are dropping it for Knock Off), etc.. The only physical booster that can actually beat him is Mold Breaker Haxorus, but I can do a quick switch to Mummy and get rid of that nasty ability for derp to derp that Hax :-) I don't have too many replays showcasing Quagsire in all his derpy glory, but I can attest that he is very effective at what he does. As a note from a lesson I learned:
Do not run Sp Def Quagsire with Curse. This is such a tough lesson for me. Before it can start to tank physical attacks, it cannot take more than 55% from the initial hit when you go to Curse. Otherwise, the 2nd hit will almost surely take you out. Some key examples are LO Lucario, Mega Lopunny HJK, etc..
DH# 3: Mega Rango
I love the movie Rango, the one with the chameleon in the desert? I may go for a Rango 2-fer and use Kecleon next month lol But, anyhoo, back to Mega Sceptile. The reason i chose Mega Scept is that it has some really key characteristics that separate it from the newly dropped megas:
1. Grass/Dragon typing gives it so many switch-in opportunities: water, electric (lightningrod is an extra bonus, but I haven't switch in on an electric move just yet), ground, grass, etc.. It is now neutral to fire (x4 ice stinks, but it's not too common outside of Ice Shard Donphan, Nidos and Mega Stoise) and is immune to Spore and T Wave.
2. It's speed is pretty crazy. It starts off at base 120, which outspeeds the base forms of every other mega and jumps to 145, which is occupied by a very select few (Beedrill, Zam, Aero, and other Sceptile).
3. Now, this is the kicker: Access to SD coming off a boosted 110 Attack. I know some people are going to say why wouldn't you go special with that 145 special attack coupled with Lightningrod? As I said before, I haven't gotten a boost once from a Volt Switch and it has no way of boosting its special attack. It has plenty of switch-in opportunities and is mainly my end game cleaner, when hazards are down, and mons are weakened/status inflicted. I almost don't bring him out unless I am 100% positive that it can get the KO, or boost for the sweep. Plus, it's Physical Movepool has Leaf Blade, Dragon Claw, Dual Chop (idea of breaking sashes sounds so much fun, but the amount of times it misses isn't funny), Earthquake, Aerial Ace, Iron Tail, etc.. It's special movepool is mainly limited to Giga Drain/Leaf Storm (-2 sp attack drop), Focus Blast, Dragon Pulse and Hidden Power of choice. Blissey and Florges laugh at you. Crobat can switch in almost without consequence.
252 SpA Sceptile Dragon Pulse vs. 248 HP / 4 SpD Crobat: 120-142 (32.1 - 38%) -- 0.9% chance to 3HKO after Black Sludge recovery
A +2 D Claw cleanly 2HKO Bulky bat with SR on the field. And Mega Scept outspeeds him easily (unless Bat is scarfed...).
So, that's my DH for this month. I really built them around the top threats in the meta atm (Mega Lopunny, Mega Gallade, HO in general, etc.). I do plan on continuing with this team to see how it does.