I chose Piplup, beacuase it is strategically the best way to go. Why? Well, considering the Water-Types offered in-game, without trading or using Pal Park, the selection sucks. Empoleon is the best non-legendary, non-traded Water-Type you can get in-game. Some may argue that Gyradose is a better choice but its typing pales in comparison to Empoleon who isn't OHKOd by Electric attacks and takes minimal damage from Grass attacks. Floatzel sucks compared to Empoleon and Lumineon and Mantine aren't even worth raising. Well, that's why I chose Piplup.