|Keep It Simple, Stupid|
You should ask yourself why you want to learn a new language. And what you will use it for.
If you don't know it yet, C is probably a good choice: It is widespread, the syntax is similar to Perl and there is even an interface between Perl and C.
Another popular choice is Java: It is a very widespread language, with a huge API for many things, including networking and GUI. And you'll forced to learn the OO-concepts there ...
If OO is relevant for you, you might also want to have a look at C++.
On the other hand you may just want to broaden your knowledge of "skripting" and learn new flavours. Then think of Ruby, Python and PHP.
Or do you want to pick some exotics? Just to think differently? Try Forth or even better Lisp. Or -in the other direction- assembler.
If you want it for business, check the domain you will work in. For financial, ABAP is probably helpful, for more mathematical oriented busines MATLAB is probably worth a try. Or learn the classical ones: COBOL respectively Fortran.And if databases are your focus, why don't you try SQL, which also fits nicely to Perl...
In the architecture they say "form follows function". It is similar with programming-languages. Decide what you want to do, and the number of possible languages narrows to very few. Or -in many work environments- the language is predefined anyways.
HTH, Rata(who has used over 10 programming-languages till now (plus some experiments in others), and thinks that the basic concepts are the important things, not the languages themselves)