Actually, Bulbasaur was axed a while ago. This is the list of starters you can get in the future (in order of what you can get first): Chikorita, Tepig, Squirtle, Cyndaquil, Turtwig, Totodile, and Fennekin. (Might be missing more, though.)
Now, I'd recommend Contrary Leaf Storm Snivy, but Serperior doesn't get Leaf Storm for a while, so that might be a problem.