I answered this before, but after 2 years I think I can get away with a new comment! My favourites are always the grass types, I just think their cool, I've never cared much for what pokemon are ''good'' in the games, I just play with my favourites!
Kanto: Bulbasaur (Obviously) but non grass type I've always liked Pidgeotto
Johto: Chikarita is cool, but my fave would have to be Totodile, just for the way he says his name and jumps about!
Hoenn: Gotta be Grovyle! but non grass type Euther Dusklops or Seviper
Sinnoh: Turtwig!! None grass type either Mismagius or Hippopotas
(I know I'm being a little unorignal with my faves being starters, but there you go! lol