Digimon! It's not much different from our world, but it does have some fantastical elements. To be a child growing up with technology and to be involved in the complex and mysterious world of the "digital" and to have those mysteries manifest as partners and those complexities manifest as stories... I think I'd love to be a part of that.
Cartoon: The world of Bee and Puppycat is so colorful and interesting, I would definitely want to live here.
Anime: Probably not the best choice since I don't watch that much anime buuuut Madoka Magica because of the idea of becoming a magical girl, fighting witches, and having your own abilities seem fun, but there is definitely cons to living here. The best alternative would probably be living in the world of Studio Ghibli or Natsume Yuujinsho due to how peaceful it is.
I'd say Adventure Time. I like the idea of having a huge word to explore. I loved the backgrounds and variety of locations in this show, And there are a ton of interesting characters, species, magic, etc. Just imagine settling down in a random little spot in this world and go exploring in the morning.
My pick would be Hey Arnold! I always liked Arnold's tight-knit community, a place where you knew the mailman and the butcher and the guy who owned the beeper emporium by name. It's a lot like our world, but it has juuuust a touch of magical realism to keep things interesting (such as the urban legends). When you walk around, you can have a nice jazz soundtrack to set the mood. And if you're ever having trouble, there's always a kind, football-headed boy that can lend you his ear and give some sound advice.