Chespin looks like he has more competitive potential than Froakie and Fennekin. I just like Froakie because it has more aesthetic potential to it. Fennekin may turn out the way everyone wants it to, so I'm not going to even start on that.
I love Oshawott, even though the name sounds offensive when said really really quickly.
It's a shame oshawott is portrayed as a hyperactive and annoying character in the anime. However, once I saw Oshawott and Ash workout together in the episode where they fight Blitzle, I was grateful for the anime bringing out his true potential.