This is the typical banlist I use:
Clauses: Standard OU. Swift Swim + Drizzle is legal.
Ability banlist: Huge Power, Pure Power, Moody, Imposter, Snow Cloak, Sand Veil, Zen Mode, Multitype, Wonder Guard, Shedinja + Sturdy
Note: Banned abilities are legal on the pokemon that naturally have them, with the exception of unreleased DW pokemon.
I'll go ahead and give you all one of my personal favorites, it's really a PITA to deal with!
Haxorus @ Choice Scarf
EVs: 252 Atk/252 Spe/4 HP
- Aqua Tail
- Dual Chop
Moxierus is really a pain to deal with. It has all the upsides of MoxieMence or Moxiedos, with the added upside of not being quad weak to anything (especially not to ice shard). Plus it has the highest base attack stat of any moxie user, which means its outrages get absurdly strong after just one KO. Definitely an unstoppable wrecking ball if you don't have any steels and it gets so much as one kill.