Will-O-Wisp Golurk
It doesn't learn this already? Anyway, it's a Will-O-Wisp that will never miss, which is nice, and cripples switch-ins with Knock Off. I feel like it may be better off attacking most of the time, but having the option to cripple something is nice.
Dragon Dance Archeops
140 Attack + 110 Speed + DDance + Dual STAB = GG It's Archy
Like Chrystal said, this will destroy everything late game (especially on hazard teams), making it a very threatening sweeper and wincon, Fortunately for the whole tier, Defeatist + Stealth Rock keeps this from being OP.
Pin Missile Skill Link Armaldo
With a Rock Blast and Pin Missile, Skill Link makes Armaldo very hard to switch into without a Bronzor (which you could run Knock Off for) and makes it a threatening tank. It's type and lack of recovery hold it back a little though.
Swords Dance Kecleon
SD + STAB Shadow Sneak/Sucker Punch is sounding really nice right now. SD + Priority is great and Kecleon is at least specially bulky enough to set up and has Recover and Drain Punch for longevity. It's low Speed and mediocre Attack hold it back, but it's not terrible.
70 Def Cryongonal
This doesn't help. 70/70 Physical bulk isn't the best and given Ice's poor defensive qualities, Cryogonal will still get KO'd pretty early on the physical defensive side. I guess it's actually worth it to run Max HP, Max Def on defensive Recover sets now, but eh.
Simple Whiscash
ALL THE WAY YES. Gives it a powerful niche as after 1 turn, it can wreck everything. It's like Swoobat but better, and I LOVE Swoobat in PU. Plus, it's good defensive typing can give it time to set up. It's just great. HP Grass might become more common because of this, Quag, AND Gastro running around, but who cares if you're setup?
My noms:
Seconding CF's Grass/Fairy Meganium
And nominating Bug/Fairy Illumise + Quiver Dance -
Illumise is outclassed by Volbeat in both PU and NU, so why not make it superior offensively? It gets access to an amazing ability in Tinted Lens, so if it came with a good set up move, then Illumise could actually be worth something. Giving it Quiver Dance let's it set up and hit everything harder. A Fairy-typing gives it STAB Dazzling Gleam, which nothing 4x resists it NU, and gives it a niche over other Quiver Dancers like Vivillon in combination with Tinted Lens