Just hit 1800 rating. My current team looks like this:
Togekiss, Bold with lefties, max HP and Def. Standard Paraflinch Set
Mega Mawile, Adamant with Mawilite, dual stabs, Sucker punch and Stone Edge.
Mega Gengar, Timid with dual stabs and sub-disable
Cloyster with Sash, Adamant with Razor Shell + Standard Cloyster fare
Talonflame with Orb, Adamant with Follow Me and Tailwind + Dual Stabs
Dragonite with Lum Berry, Adamant with DDance, EQ, Outrage and Fire Punch
Notes on each one:
Togekiss is pretty solid overall. I stingily think this (Paraflinch) is the best set as Gleam and Aura Sphere don't hit hard enough even when super effective to justify their use over this set. The Paraflinch core, although definitely has some trouble with Electrics, mostly gets the job done while keeping Togekiss healthy. Roost is necessary to tank hits, and Nasty plot is great for setting up on weaker mons that can be out healed with roost. Max Def is better then SpD right now IMO since there are a much larger amount of Physical Attackers. Being able to take 2 hits from Talonflame and live is just too important to give up. Togekiss is great for a team looking for a check to the glass canon speedsters out there like Mega Gengar and Greninja, as Twave is pretty much lights out for them.
Mawile is alright I guess. It gets the job done, although I suspect that Mega Kangaskhan might be better at this role. That being said, those looking for a powerhouse Fairy should look no further. This thing punches holes in everything. Speed is the biggest issue, but smart use of Sucker Punch can go a long ways. Stone Edge I'm iffy on. It's possible that Swords Dance would be better.
Gengar is pretty good. Honestly, keeping levitate when megaing would usually be better then getting Shadow Tag, although it does allow for some mind games against Earthquake users. Make sure you don't need the immunity before powering up. Or what might just be better is using Normal Gengar. Speed is nice against Greninja and Noivern, but that's about it, and Life Orb hits just as hard as Mega. At any rate, Sub-Disable allows for the most survivability for Gengar, and is good for scouting purposes. Having a Sub stick is often times game. I go for Sludge Bomb over better coverage options to take out Fairies not named Mawile and because it's the highest base power stab move Gengar learns, which means that it hits stuff neutrally the hardest. You can throw in Focus Blast here if you really hate Tyranitar. Tbolt and Gleam don't lead to shaving off an attack for the mons that you would actually kill with them, (Still not 1-shotting most dragons with only 80 base power) so I don't see much reason to run them. As for the best set, it might be the 3 attack + Destiny Bond set, although it's a bit more suicidal. Lastly, Perish Trap is garbage here since the format is full of aggressive mons that can deal more then 3/4ths of its heath in the turn it goes for perish song.
Cloyster IDK. Its sash gets popped by literally every special attacker in the game it doesn't resist. That being said, if they don't have priority/WoW/Twave, this guy can go the distance. However, most good teams have at least one of those, so it's more of a noob stomper then a high level mon. It usually rides the bench, but smart use can early steal games. Not totally sold, but if you're looking for ways to cheese free wins other then minimize spam, this is a good place to start.
Talonflame is Talonflame. The core is its duo stabs, everything else is just gravy, with this set being clear evidence of that. Me first is a toy move I'm using just for kicks. I barely use it, but it does has its uses, largely outraging Dragons. Every once in a blue moon it will be useful and do stuff no other move can do. Those times are few and far between though, and you're largely better off using something else. Tailwind combos well with Mawile and any other slow but strong mons you may have. You can run any other move you want in those 2 slots, just make sure you have Brave Bird and Flare Blitz. For what it's worth, I think full aggression is better then the Roost/Lefties sets. The 3v3 meta is much more aggressive and there are much better leftovers users out there, which matters since you only get to use 1.
Dragonite is a Champion, seriously. No entry hazards means Multiscale 24/7 which means you're almost guaranteed a Dragon Dance. Full Health Dragonite beats every other dragon out there while usually getting a Dragon Dance in, just watch out for Scarfers and Sash users. Lum Berry is amazing on this set. It makes Outraging much more safe if they don't have a Fairy since it can remove the confusion. It also lets Dragonite beat most sets of Rotom-W since most rely on WoW to cripple Dragonite, and Dragonite can 2-shot Rotom with Outrage. Because of this, Dragonite is a good lead against a team that you suspect will try to use status effects. Seriously, Dragonite is a beast, and arguably the best offensive Dragon right now, beating out even Garchomp IMO. Garchomp needs to use a Band to reach the power of a +1 Dragonte, and still won't reach the speed, but Dragonite doesn't have to deal with getting locked into a move. Losing immunity to Electric and TWave sucks, but not being able to be 1-shotted by almost everything is really good. This guy is greatly underrated, (Given that he isn't seen anywhere near as much as Garchomp) and if you're looking for some more firepower while being deceptively bulky, Dragonite has plenty to offer to the table.