Totodile is the **** man. For some reason he's always been my favorite water starter. I mean, all the water starters are cool (except Oshawott) so it's hard to pick.
I honestly like them all but oshawott. For the other starters i like their entire evolution lines, but not oshawotts. I like oshawott as a single pokemon, but wtf were they thinking when they made sumarott??
It's a toss-up between Squirtle and Totodile because Blastoise's design is really solid but I have good memories of using Feraligatr in my original favorite Pokemon game, Crystal.
I love the Piplup line but Empoleon's stats are really mediocre. For Froakie, Greninja has great stats and Protean is a wonderful ability, but I don't feel much attachment to it. I find the Mudkip and Oshawott lines pretty bland, but I don't hate them or anything.
I ended up going with Totodile because it's the one I've been most attached to over the years.
I voted for Piplup. I love this Pokemon! Since I had him as my starter in Pokemon Diamond, he quickly became one of my favorite Pokemon. My second favorite is Oshawott.