The first game of pokemon I played, I only used my starter for the entire game. It was a squirtle. Although, I did catch pokemon in the wild, but I never bothered leveling them up. By the time I reached the Elite Four, it was a level 90 juggernaut of a blastoise. It overwhelmed the Elite Four up til Gary, where by that time it was too worn out to continue fighting.
My most recent game with Soul Silver, I stuck my starter in the box as I had caught a Vulpix. As Ninetails is my favorite pokemon by far, and because I didn't need two fire pokemon in the my group, I ditched my starter. I've never regretted it. Ninetails is a good pokemon, and it's not too common to see pokemon weak to fire, anyway. Most pokemon battles I can take on with either my machamp or my dragonaire.
I wish they would change up the starter pokemon types. Psychic, Dark, and Fighting is a triangle which could work, and I could probably find more.