I don't really have a particular favorite.
Hydreigon - b/c he has good stats, a great movepool, unique typing, and an awesome design. And it's just awesome.
Volcarona - again, good stats, a great movepool, unique typing and a good combination, and a great design. It looks awesome.
Zangoose - I dunno. I just like it.
Magikarp - you can't dislike Magikarp.
Hydreigon - b/c he has good stats, a great movepool, unique typing, and an awesome design. And it's just awesome.
Volcarona - again, good stats, a great movepool, unique typing and a good combination, and a great design. It looks awesome.
Zangoose - I dunno. I just like it.
Magikarp - you can't dislike Magikarp.