They're all so cute. My first Pokemon game was Crystal, but sadly someone stole my game, I got yellow after that. One thing I didn't get about Yellow was Green (or Gary in my game, I named my character Ash) getting Eevee instead of Squirtle, it was supposed to follow the anime right? It can't be type advantage since if you do things the right way his Eevee can be a Vaporeon.
To be honest it wasn't until firered that I was finally able to pick from these three, I chose Charmander of course, I love charizard. He may not have been my official first Pokemon (That honor goes to Cyndaquil and he will always be number one to me) But he was definitely a powerful ally on my team.