No they offer relatively easy to get fire/water/electric types that are great in gyms. None are best at what they do, well except Jolteon, but they give new players a good start.
As for water types, Omastar, Gyarados, Lapras, Poliwrath, etc all can be better than Vaporeon depending on the foe.
Flareon is basically a wimpy Arcanine, and Jolteon just doesn't have viable competition.