Get one that can use Spore and False Swipe, like Shroomish or Parasect.
I got my haxorus with false swipe, surf, cut and strength. You all know what kind of pokemon that makes him lol.
I use my Gallade with False Swipe, Hypnosis, Protect and Thief (For use on Pokemon with Wild Held Items), but I'll be trading Protect for a high PP move so I don't have to always use Thief...
But be careful with False Swipe cause some Pokemon know moves like Take Down and they might faint.