I'd say Haskell. But please read 'Clean Code' by Robert Martin as well. By reading the first 10 chapters (you can go through them in 2-3 days) you'll be automat

I'd say Haskell. But please read 'Clean Code' by Robert Martin as well. By reading the first 10 chapters (you can go through them in 2-3 days) you'll be automatically better than 50% of the professional developers out there.