English, for me. I have to say, including a poll in this discussion probably wasn't the best move. It also wasn't implemented very well.
First of all, you neglected to include English, a major international language. Presumably you are a native speaker of it, and it may have slipped your mind that there are others who aren't
Secondly, there are thousands of languages in the world [edited - see below]. A poll is therefore unnecessarily restrictive.
If you want a language that's not my native tongue and not English, then my favourite would be Irish.
(I'm sorry for coming off a little negative, by the way.)