TL;DR doesn't matter, just have a team with good coverage.
Assuming you're playing Red/Blue/Yellow, there is no best/worst, but Charmander is weak to the first two gyms in the games, Squirtle is effective against the first gym, and Bulbasaur is super-effective against the first two gyms. By the time you've cleared those, you'll have an adequate team to take care of other types.
You can catch Nidoran before the first gym to help Charmander, as it learns Double Kick which is super effective against Brock.... however Nidoran is also weak to water type (the 2nd gym). Which is when Pikachu in Virdian Forest will come in useful.
Or just, you know, go with your heart.