While the battle bond is indeed nice, I felt the journey that Chimchar traveled was far greater, particularly when it was trying to prove Paul wrong for abandoning it but also Ash for believing in it. I'd also put Ash's Snivy up there instead of say Snorlax. Despite the unpopularity of Unova, Ash had a few notable Pokemon who had unique personalities and were strong as well. I felt Snivy was Ash's 2nd strongest Pokemon in Unova and even Trip or Ash's rival for that region commented that his Snivy wasn't that bad. Otherwise not a bad list.
Personally I'd go for Infernape over Greninja myself (and Swellow over Snorlax for being the one bird that seemed to had a decent amount of battles under their belt) but this list is very solid kudos Kostas for the great article! Very good opinions here haha.
Gibble, I've never loved something more. It's Draco Meteor landing each time on Piplup is just hilarious. Watching compilations of it, there's never been a moment I haven't laughed. The cave is just the cherry on top, finding a separated Piplup by using it's Draco Meteor. GOD DAMN GENIUS. Of course it wouldn't be complete without Piplup's reaction.
Snorlax is my favorite Pokemon of Ash's. I think the article is fairly balanced. personally, I would rank Infernape higher but since I've never finished xyz, I think greninja's position is fine. well done!