best programming language

I am currently learning java, but I've heard that it isn't that useful.  What is the best programming language to learn, in your opinion?

>>20
Following tail-recursive function, written in Lisp DSL, finds first matching point on a line.

searchLine _   e e -> e
         ; f f:s _ -> s
         ; f   s e -> searchLine f s+(map sign e-s) e

Now, please, implement it in Java.