I already live in Germany. I think if it was just a year in each place I'd pick very differently to places where I'd choose to stay permanently.
USA definitely on the list for a year - seems like a fascinating place to live but I would be too nervous about medical debt to want to live there permanently.
Somewhere in Asia, probably Malaysia or Singapore? I would love to say Japan or South Korea just for the total difference in culture, but I think they speak a lot of English in Malaysia and everyone I know who has lived in Singapore absolutely adores it.
Australia for sure, though I'm terrified of the summers and the wildlife. I would have to live next door to my Aussie friend who moved back there and go crying to her for help every time!
Somewhere in Africa, maybe Cape Town as I have a friend who lives there too. Maybe I would just pick a friend to live near each year! If we are doing that, then the Asian country could be Japan, because DH has a friend who lives there.
Not sure what to pick for the last year. I'm torn between trying to do all of the continents and picking South/Central America, but unsure which country exactly, there's no stand out place that makes me think yes I definitely want to try that. Maybe a Caribbean island? They look beautiful and I have always wanted to go there.