SD Haxorus is a good one. Don't bothering running Taunt unless you're DEAD SET on Haxorus being used 100% for stall breaking. SD / Outrage / EQ / Brick Break with a draco plate gives most stall teams headaches. +2 Outrage w/ Draco puts a ton of pressure on Skarmory so it can pretty much only Roost, or risk being put into to KO range for pretty much anything else on your team.
This. So much this. However, know that the above set is the ONLY haxorus set in the game that will, 100% of the time, break through Skarmory, regardless of whether it's carrying leftovers or shed shell. SD on the switch, taunt in case of whirlwind (or an attempt at roost stalling out outrage), and outrage twice for the guaranteed 2hko after one brave bird recoil, even factoring in minimum damage rolls for all three and leftovers (even without entry hazards!).
The only way skarm wins is if it guesses you're going to taunt, and brave birds twice,
and gets high damage rolls on both,
and haxorus has sustained some previous damage (so, thats not gonna happen often). The alternative is switching skarm out to save it, and in the process allowing some poor poke on your team to take a +2 outrage. As far as i know the only thing that survives a +2 outrage and can attack back before getting 2hko'd is scizor, who's still ohko'd more than 50% of the time after SR, and only attacks back faster because he has bullet punch).
Brick Break is really only used for ferrothorn, who's 2hko'd by +2 earthquake anyways, and taunt is still useful if you fear leech seed (or twave, but running draco plate might bluff lum berry).
To be quite honest, I personally think that SD Taunt Hax's combination of surprise value and pure power makes it the best wallbreaker in the entire game. Being able to KO its only usual counter (and a thorn in the side of physically based HO) means it should be a mainstay on any team in need of a Skarmory lure.