well i would be either
 

sakura from tsubasa chronicles or zero from code geass
or yuuki from vampire knights or naruto from naruto shippuuden
or the pink pearl voice girl from mermaid melody.

yuuya aso from super gals

Maybe.... Haruhi from Ouran High School Host Club?
Because she's so emotionless, haha...
Also, Konata from Lucky Star! She's so funny, and I'm so jealous that she has so much manga and video games.

manga character
 

I definitely want to be L and no one but L!!!

I don't know, but I'd propably be L from Death Note, since everyone keeps telling me "dude, you're just like L!"

I would want to be Sesshomaru. I like that he is powerful and confident and that he keeps to himself and does things on his own.

Satoshi Hiwatari, He's so ultimate.

If you were Sakura, I would hope that you beat the shit out of Naruto. :)