>>30940241Charmander was my starter back when I played Red during Gen 1. Back then I had no idea what I was doing, and admittedly used him so badly so many times, but Charizard was with me the entire time while learning pokemon and getting better at it, all the way to the Elite Four which has made him my all time favorite. Gardevoir I just discovered while using her while playing X, but her typing with Fairy has been a solid addition to more than one team. I think she has a solid design, and adds an aesthetic change of pace to my team.
Greninja was just my first solid water type starter that looked awesome, and kicks ass in game to boot. If there was one of the three liked for shallow reasons, it'd be him more than the others, but they each are liked at a fundamental reason because of their comat potential, which includes the typings they bring to a team, and/or access to particular attacks they offer.