I can tell I'm going to get ninja'd.
EDIT: Nope, not ninja'd.
Well, Luxray GL Lv.X is so popular for it's Poké-Power, Bright Look. It's basically a free Gust of Wind when it's leveled up. With a single energy and an Energy Gain, Luxray can do a quick 60 damage, which can kill a lot of Pokémon with weaknesses to Lightning. Or, if you have something that can kill the Pokémon you sent up, simply use its free retreat to switch to something else. And since it's an SP, you can use Pokéturn to constantly use its effect.