Hi, I'd like to join this club:
Starter Pokémon: A Charmander named Ryuu and A Totodial named Tsunami
Why would you like to join the club?: No matter how much you might want to deny it, your Starter Pokemon will always be the most important member of your team. Its your first ever partner when you start anew and will always be your most reliable companion on your journey (honestly, you can over- grind it to high levels in the early stages of the game because, no matter what, it will always listen to you).
Onto the current topic;
Legendaries would not make good starters as you would want your starter to evolve. Pseudo- Legendaries on the other hand; I wouldn't mind if Dratini or Larvitar was a starter.