I started with Red because I always viewed it as the superior of the first two games for no real reason, but my starter on that game was Squirtle. When I got Blue, my starter was Charmander. I've always thought that was kind of funny for some reason.

Yellow was definitely my favorite of the 3, though. That first battle is really hard considering you start off with Pikachu. I'm pretty sure I got a Nidoran for that fight, but I can't remember my starting 6 Pokemon.