Who wants to help me choose a country to go to (foreign exchange program through a rotary) for 10 months :D?

The Netherlands would definitely be the most gay friendly. If you speak German, Dutch will come almost instantaneously. I have a lot of cousins in the Netherlands and Belgium, all of them like 12 to about 17, and they're all pretty liberal about homosexuality.

In fact, when you become a citizen of the Netherlands, you are required to watch this two hour film called 'Naar Nederland' (to the Netherlands) where you see nudity and men kissing and stuff. It is meant to show foreigners that this type of all-accepting liberalism is an integral part of Dutch culture. You will definitely feel welcome.

Most Dutch kids are super into American culture and will tend to be excited to both share their desire to travel there or hear about your life there.

My overall experience with Dutch, albeit my family is all Dutch so I may be biased, is that they are warm-hearted and friendly. Often, people take awhile to open up to you, so be patient and friendly.

Germany would be great, too. Everyone says big cities are better than small towns in respect to liberalism but I really don't see you getting attacked or anything.

In every situation, though, you should be careful about coming out to be people. No matter how liberal or open the environment is, there are creeps who transcend human decency. Just a word of warning.

Overall, if you're interested in the Netherlands, consider it.

Oh, with English, every Dutch kid I know your age speaks English better than you or I. They start young and are all, basically, extremely fluent. Most of sort of funny accents, but you will have no problem communicating. If they have trouble with English, they speak German and French. It's a very multi-lingual culture.

On your list there is only Germany and the Netherlands as non English speaking.

Of them, I guess the Netherlands are generally more welcoming to gays, allowing marriage and all.

But 15 year olds may not be as ready to accept it, so be a bit hessitant when telling your classmates, wherever you go.

All Dutch 15 year olds do speak a certain amount of English, but not as good as native speakers.

And you will have to sit through classes in Dutch too, (unless you go to one of the rare English language schools.)

Germany might be easier for you, in respect to language, as you already know a bit of the local languages. And all German kids will have had several years of English lessons too.

The most gay friendly places on your list are the Netherlands and Australia. And both would be fine if you were American.

England and Germany are fine if you are in a big city like London or Berlin, but not as much in small towns.

If I were you I would choose Netherlands or Germany

England

...Elton John's accepted

Go to Australia, meant to be beautiful there!