I was born in Germany (my parents lived in Darmstadt for 8 years, and had my brother and sister there too) but we came back to the UK when I was just 5 weeks old. I WISH they'd brought us up as bilingual. They still talk German to each other on occasion and watch German films/read German books. I officially learnt at school but the teacher was crap and I have no brain for languages so I've forgotten all but the most simple words. It would really have opened doors for me if I'd been brought up understanding it. If I had a magic wand and could pick just one other language to be fluent in, it'd be German.
What about you? How many languages do you speak already and which new one would you choose? Why?