I say Ninjask. Max out HP and Speed. Sub it up, then Agility through the sub. You'll get a Speed Boost. Then you can Protect through their next move, get another Speed Boost. Baton Pass to Granbull, and you'll have the speediest Granbull ever. You can add Swords Dance too, and Baton Pass the attack boost as well. Although this will make two of your pokemon weak to fire, I think it's worth it. It might be a bit predictable, but when are you ever going to use Ninjask to actually fight?
I prefer Ninjask over everything else because it has Speed Boost. You don't even have to add Agility.