My first runthrough is just to see what there is to see. I think my favorite starter might be Oshawott, just because I love the concept of Samurott wearing scabbards on its arms...but for my first runthrough I actually chose Tepig because I figured having a Fighting-type would be useful in the second Gym. Also, I haven't bothered training a Lillipup or Patrat because I figured raising such early-game Normal-types would be a waste of time in the long run.
Big mistake. The two well-trained battlers on my team are now a Fighting-type and a Grass-type, and Pidove are handing me my ass out here. I'd better find and catch a Blitzle soon.