Squirtle in firered
solely because i thought it looked cooler than bulbasaur and i knew how everyone picked charmander through reputation. From then on i silently committed to pick water starters in every game
I was gifted a copy of Pokémon Red from my mom when I was 8 years old, and I originally chose Charmander because it was my favorite Pokémon from the anime at the time.
If i remember correctly, it was Squirtle. I choose him because it seems cute for me, and i did that on Fire Red in GBA. It was good starter back then (at least for the adventure)