Kanto: I would pick Charmander; because in my opinion while Bulbasaur is a dinosaur and Squirtle is a turtle that gets cannons; I always liked the idea of having my own personal dragon to use.
Johto: Cyndaquil; because Typhlosion is quite awesome if a bit lacking in the early game.
Hoenn: Blaziken; because while Swampert has the least weaknesses it's not exactly based on my favorite mon, and I like Fire/Fighting lightning bruisers more than super fragile Sceptile.
Sinnoh: Piplup; because while it starts out as being quite derpy it ends up being quite awesome.
Unova: Oshawott because it's a samurai.... do I really need to give you another reason?
Kalos: Froakie; because while I am quite happy that they broke the fire/fighting mold with Delphox; it's a mon that looks like a woman, but has a 75% chance of being a man; that and the fact that I don't really like most pokemon that are four times as weak to a type, and the fact that Greninja is the jack of all trades, and if used correctly; the master of all.
Ps: I agree with you Juuzou why is it that no one ever expects extrasensory?