I'd be able to use an entire team of dark types. :3 Absol, Houndoom, Mightyena, etc, are all dark types, and they are awesome. x3 I I wish there was a dark-fighting type, It'd be immune to Psychic, super-effective against Ghost types (thanks to it's dark-type), double-resistant against other dark types, able to take out ghost-types with a dark-type move (that you can't take out with a fighting-type move), etc.
I'd be sure to include Tyranitar and Honchkrow, in case I wanna go for some 2v2 Earthquaking. Shiftry or Cacturne would be useful, as well as Sharpedo or Crawdaunt, so I can have a Grass/Fire/Water combo on my team. Weavile'd be good for fast sweeping, but Sableye and Spiritomb have no weaknesses. I'd also think about using Darkrai, if I was allowed to use ubers.