My Vote this time might not be as fair...but....I go with Totodile. And for backup reasons, I would say I chose Totodile for him being a starter :P
But Seriously, come to think of it, Regional Birds have no Personality...Well, I don't want to go far by saying NO but you know what I mean.
Besides, Tranquil is the worst Regional Bird I've seen :( , yes this is where it gets unfair. I personally don't like him, it is so Bland in my P.O.V sorry. Above all that, UNTIL NOW, Tranquil have not done a thing, we didn't even see him get some character development at all! Since Totodile is a starter, he is most likely to get more Spotlight. In terms of Design, Power, Personality, Comedy and so on.
So, Totodile for me :/