Jirachi ! Why ? Simple ! I could make ANY wish I wanted and it would come true. Maybe even more than one wish, i'm not sure if Jirachi can grant more than one but i'm sure it can grant at least one, and that would still be really cool. =)
Umm, how about Tropius... It satisfies my want of Grass types, it can fly, and provides food (Bananas FTW)! Also, it's one of the underused Pokemon that looks cool. There are many others I want though... but Tropius would be freaking awesome!
I'd have a Charmander to evolve into Charmeleon and when that evolves into the creator... who's going to mess with a big red dragon that breathes fire, eh?
The trouble with Charizard is the feeding... First, I'm a vegetarian so I wouldn't buy meat. Second...
Me: Got any food for a big dragon?
Shopkeeper: *Rings hospital for mentally disabled people*
Porygon would be a lot easier to look after. I spend half my time on my computer anyway.
(For those who are wondering, the other half is split between school, playing one of many pokemon games, eating, doing homework, drawing and sleeping.)
I would have a ghost Pokemon, perhaps a Gengar or a Misdreavus. Pokemon can't die but humans can, so when I 'went' it could keep me company. We could play spooky pranks on people! Wow that was both gloomy and entertaining...