Pokémon FireRed and LeafGreen/Route 17



Route #17's brutal slope drags you downward unless you hold the or  buttons to steady yourself. It's easy to get caught by surprise by the trainers as you whizz down the hill, so make sure your first slot has someone to handle the variety of Poison, Fighting, and Electric pokemon carried by all the bikers. As long as you're prepared for the occasional trainer battle, there's no reason not to speed to the bottom.