Hm, when I've played Pokémon Pearl for the first time, I chose Turtwig as my starter pokemon. I thought it was a pretty cute pokemon, and its defense was pretty good! As it evolved, yes, it became a little bit on the slow side, but, it's defense more than make up for that anyway. Gym battles weren't that bad when I used it either! Things became a little tricky over at the Snowpoint gym though, because Torterra is 4x weak to Ice type moves, and so, I had to use a little bit of strategy, but no problem. In the end, it was pretty effective against Cynthia's Garchomp as it took its. I took a while to beat her, but, success! When I played Pokémon Platinum more and more, I used Chimchar more often. That was around when I started to like pokemon like Gastrodon, Roserade, and Togekiss, in which, I don't really like out have pokemon of the same type in my team, so, Chimchar was a pretty good pick for that! It wasn't too bad either; it was way fast, and pretty powerful when It evolved to Infernape!
When I was playing Pokémon HeartGold for the first time, I just stuck to my traditional method - I chose Cyndaquil as my starter, because that was my favourite starter to use back when I've played Pokémon Gold or Pokémon Crystal. Again, nothing much changes, except for the addition of some moves like Rollout which was handy against Lance's Charizard or some other Flying/Fire type! It's flamethrower is super powerful in that game too, when it evolved to Typhlosion.. I dunno how, since I didn't remember Typhlosion being that fast and that strong in Pokémon Gold, but hot dog, who was I to complain! <3 Over all, it's still a wonderful pokemon, and fit well on the team I had planned (Lapras, Scizor, Golem etc, etc).