Some languages to learn...

Arabic,
for being able to communicate with locals in at least 20 countries, most of whom are the friendliest people in the world. Because it's the mother tongue of 25% of my ancestors.

French,
because one feels uncultured if one doesn't speak any French. For understanding Jacques Brel's songs without having to consult 97 dictionaries.

Hindi,
because three years ago I taught myself how to read and write script and it was immense fun. I'd like to brush up on the alphabet and then learn how to say some things.