Easy?! This isn't a criterion to choose a language
. Man! Through the language you can understand a culture deeper and you'll have a best sight about its aspects .Rather say which language you'll need for your career or something similar, kinda an ace in your C.V. cards.
Besides English, I think that German, Japanese or French will be a good choice. All what you need is the burning desire, strong will and especially patience and persistence.
Finally, I hope you a good luck