I think piplup is a good pokemon to choose because it has great defense, good for versing a rival, AND it goes with the story line cuz in the movie twinleaf town people like piplups!!!
Piplup can also get fast using items,so then you would have the perfect punch!!!!
Piplup is also good against lots of gyms, and when it evolves into empoleon, it is an awesome pokemon!
Piplup should also be chosem because unlike other pokemon, it dosent have many weaknesses as it levels up.
Piplup can also easily beat a chimchar and turtwig.
ALSO piplup is good for the elite for as an empoleon because of its low amount of weaknesses
This is why piplup is an awesome pokemon to choose at the beggining of the game.