Pokemon, easily. Catch 'em all... not so much. Get myself a Blaziken, wipe out everyone and everything.
Star Trek: The Next Generation. My genre savvy would go a looooong way to getting captain.
I thought about My Little Pony, but then I remembered they don't have all the music I so dearly love. Or the games. Or the food. Also, I really doubt I'd be associated with the mane six, and the only exciting things in the world happen around them.
Also, no human ladies anywhere, and... well, THAT'S not gonna happen.
So, sadly, no living with the ponies, as I'm certain I would go bat-squeak insane.
Justice League. I think I could make it as a powerless superhero, if I train myself hard enough. And again, genre savvy.
The world of the Belgariad/Mallorean. Already I've lost probably 95% of you. The rest of you, you know what's up. When I fulfill my Purpose - I'll still be alive, because I'm automatically one of the good guys - I get rewarded by the Universe with a nice life.
Oh wait, same problem as the pony world. Food is good, but no games or music. Nuts.
Yeah, definitely the Pokemon universe. Specifically, I'd prefer Hoenn or Sinnoh, though Unova is nice, too.