I'd want to be Italy! But I'd also like to keep being a girl, so maybe Fem!Italy? Mainly because I get to eat all the pasta I want and so I would be able to live in Italy! (the country) I've always wanted to see it!
Prussia~ Instantly. No not because he's awesome and everyone knows it or that he's my most favorite character but, because of his complete and utter amazing confidence. He embraces a lot of challenges with a huge grin and even if those challenges are too difficult and he ends up failing in some way it never shatters his confidence or self-esteem. I just admire that so much about him. I love everything about this man. He's amazing and I just completely admire him to death. If I could be anywhere near like him even in the slightest I would in a complete and utter heartbeat.
ZE AWESOME PRUSSIA OF CORSE!!!!!!!!!
but in all seriousness, Prussia seems to have the most fun and gets all the sarcastic and funny lines and quotes. I also think that maybe Romano as a second, but definitely Prussia!