Well I would begin by choosing Charmander. After embarking on my Pokemon quest I imagine I would just grind like hell and raise him to level 12 in time for my big duel with Brock. I'm sure I'll have caught a Weedle right now and raised it to be a Beedrill, and maybe have a Pidgey but Brock's Pokemon have such little special defense that I could probably do the whole thing by spamming Ember (spamming Leer whenever his Onix uses Bide, of course). After acquiring the Boulder Badge I would go through the legendary Mt. Moon, where I will encounter many unique Pokemon across the way, such as the magical Clefairy... along with this weird group of people who call themselves Team Rocket. I'm sure there's nothing to fear from them, they mostly have Rattata and Zubat, no big deal. Anyway, after what seemed like hours I emerge from Mt. Moon. I don't think my Pokemon are too injured, so I'll see if I can't win a nugget! The money sure could come in handy. But gosh darn that Fagballs Oak! He managed to get ahead of me, and his Wartortle is so strong! I'll go back to the Pokecenter, and try and raise my Pokemon as much as I can... but between a Charmeleon, Beedrill, and Onix I don't know if I'm ready to face Fagballs, much less Misty! This is going to be hard.
Eventually I'll defeat Fagballs, and go win that nugget! But again... a mysterious Team Rocket minion wants me to join them. I want to join! I'm fairly sure I could run the joint in a week. Too bad I'm mute. Oh well, that's what I get for my parents making fun of the crippled kid in high school. Anyway, I take my nugget and sell it at the Pokemart. 5000 moneyz?! That's great... I think. I still haven't figured out the value of 1 moneyz. Anyway, apparently $5000 goes a long way, because I spent the next week in a barbituate-induced stupor, and when I came to I found myself asleep in front of a gigantic cruise ship! I now have a Charizard, Snorlax, Kabutops, Machamp, an abused Bellsprout that only knows Cut, and a normal mouse which I seem to have painted yellow, and dismemebered him so he would be crammed into the Pokeball.
Somehow, there is a truck in front of me. I imagine that my wacky antics have resulted in this truck appearing. I can hear the cries of what seems to be a psychic cat, so I have my Machamp use Strength. The truck moves out of the way, and it turns out the psychic cat was Mew! So I capture Mew, teach him Fly, trade him for a Scyther who must be better at flying, realize he can't fly, catch a Pidgey, and fly across the English Channel.