The first time I played FireRed, I chose Charmander, well, because he was the only starter I ever chose back in the old games. I never choose, NEVER, Bulbasaur; I dislike grass Pokemon. The second time, which was in LeafGreen, I chose Squirtle.
As for the RSE versions, I tend to mix them up; although I dislike grass Pokemon, however, Treeko is too cool to miss out.