Let me recover my memory.
I am unsure in LeafGreen whether I started with Charmander or Squirtle in my first try. But I do remember a long game with Charizard. Anyways, on all subsequet replays, I chose Squirtle, and I am now having a Squirtle-Only Run (with some revive slaves and hm slaves, XD).
In the RSE games, I rarely ever use anything other than Torchic. Treecko is overrated and Mudkip is, well, Mudkip.