>>33815887there are good alternatives to all of them battle wise so just use what you like
personally I would lean to Oshawott because the only other Unovan Water type I really like is Frillish, but I don't really care for Jellicent, while Snivy gets preempted by the Cottonee and Sewaddle lines which are both some of my favorites, and Tepig has to compete with the Mienfoo and Litwick lines for Fighting and Fire respectively but those ones are at least pretty late game unlike the Grass-types