Ugh, i cant really answer this question, just one is a real pain in the ass. SO:
Bleach (as long as i can be a soul reaper)
Negima
Naruto ( as long as i get some ninja training)
One Piece
To Aru majutsu no index
Rosario + Vampire (as long as i get to meet some youkai)
Ubel Blatt (as long as i get to know the truth)
Full Metal Alchemist
Soul Eater (as long as i can be a witch a weapon or a tech)
Psyren (maybe)
Nuraihyon no mago (as long as i get to meet some youkai
Tsukihime/ Fate stay night (they are in the same awesome world)
Ichiban ushiro no dai maou (as long as i can do magic)
Jio to ogon to kinjirareta mahou (as long as i can do magic)
Tower of god (as long as i get in the tower)
Yeah, I probably have more but I cant be bothered to go on. I know some arent anime but they are manga so i'm saying thats close enough.
Once i die and if god exists im gonna talk to him about making these worlds real, so hopefully I might get a shot in one of them, fingers crossed i guess.
I would like to show up in "Tytania" as till now that anime still show up in my brain sometimes. Battle in the ship and shotting others also not to forget many of political struggle. i would like to live in that world. If other maybe To Aru Majutsu no index world, I would look for ultimate power and fight Touma.(for dead maybe)
If I had to choose one, it would have to be Pokemon. I'd leave home at 12 (or even earlier) and go on all sorts of adventures, make some life-long friends and make a name for myself. It would be me, my partner Growlithe/Arcanine, my other pokemon and my friends versus the world in friendly competition. It would be incredible.
If I couldn't have that, I'd love to be a member of the Straw-Hat Pirates in One Piece. So many adventures!
To LOVE-Ru, or the world of To Aru Majutsu no Index/Kagaku no Railgun. I would love to have a harem of girls like Rito, but being in that awesome Academy City with Misaka Mikoto would blow my mind. Or Code Geass too, if I'm feeling a little evil ^^ Hopefully engage in some Knightmare battles and meet Anya :D
cuz traveling da cosmos with 3 beautiful women, a genius hacker, and the most powerful personal ship you can have while escaping your debt is just so damd awesome
or
Air Gears
cuz having MILITARY GRADE FUN is the best! especially when you can do far more outrageous tricks NOT POSSIBLE WITH REGULAR SPORTS MEDIUMS
Nnnhg, tough question, there are too many worlds to choose from!
If I had to choose one, I would want to be in "History's strongest disciple" (in place of or as Kenichi) mainly because I would positively enjoy being trained by masters of the art.
However, when it comes to more supernatural, I would love to be in the "Bleach" universe (As a Shinigami of course) especially in with the 11th squad, high ranked :D
probably negima!
but only if i can be in ala alba as one of negi's pactio harem~
xD
i want amazingly cool powers (+ maybe cute outfit change) i can summon at whim.
plus, hello, 31 girls in that class.
that's plenty of fair maidens for me to try and pickup.
current ala alba:
i'd love to visit the world of bokura ga ita to stab some sense into that shithead yano. 'U'
err, i mean slap, yeah... anyway.
either way, no CLAMP anime or manga for me!
i love CLAMP to tiny bits and pieces,
but their plot twists, uhh yeah someone would try and kill me. ;^;
plus i'd never get to kiss my love interest.
ever.
not even once.
.... ;^;
edit: urge to draw my own pactio card. :I
LET'S DO THIS.
-runs off-
I'd love to be just some random citizen in Ikebukuro in Durarara!!, hearing the neighing "vroom"s of Celty driving around the city each night, being kept on my toes whenever Shizuo sees Izaya, keeping a keen eye out for fly-by trash cans, vending machines, and other ridiculous, large, objects being thrown around. I think there'd be a lot to do and see in the place, and I'd love to be in there with them.
Macross frontier if i can get ranka to give up on alto or pokemon because i want to raise an arcanine and the afrobull from black and white, not to mention the ice cream cone.