That probably much depends on what you are doing or want to do, and to chose a language that best complements what you already know. If you want to make safe be

That probably much depends on what you are doing or want to do, and to chose a language that best complements what you already know. If you want to make safe bets, pick one from the "most popular" chart that you did not list (JavaScript, Python, C#, Perl, and Ruby). However, some more exotic ones might be worth your time, too: Scala might become more important in the future, for example, as it offers concurrency support. Same for Clojure that has some popularity on HN at least. On Erlang I probably do not need to comment, either. An if you work Apple stuff, Objective-C, naturally. If you go into games development, Lua is an option. Etc., etc., etc. In essence, it is not very hard to pick up a new language - the real work is knowing an important framework that the language provides really well; Which ties in with what you want to do with it in the first place, again... EDIT: And one more thing occurred to me: With NoSQL loosing popularity currently, I think having good SQL skills will be of more value once again. And, truly efficient DB management (and design) cannot be done from some ORM alone; designing well-formed Schemas and writing good SQL (or knowing how to use an ORM to produce the "right" SQL) is an art that should not be underestimated.