Chinese, French, Spanish or Italian?
Where are you from? And what is learning other languages for?
Mandarin/Chinese is spoken by a LOT of people, so that figures. Although I am not sure how relatable or worthwhile learning Chinese to interact with the people who do talk this language. It is pretty difficult learning Mandarin and if you don't have lasting plans of using it, I am just not sure it'll be worth it.
Although, about a year or two ago, I aspired to study the language.
Spanish is relatively easy to learn, so go for it. And it's very common too.
French and Italian are a bit of a wildcard for me. Try Latin, just for fun.
Learn Korean/Hangeul too
