I program in VB, C, Perl, AWK, ksh, bash, and Object Pascal.
Basic perl is easy to learn if you know C, but perl has a very wierd syntax that a lot of programmers don't like. I like it but hey!
VB is just for windows and it is VERY popular in the "real world".
The closest thing to VB for Linux is Kylix, but it uses the object pascal language.
Perl is still my all time fav....they is so much code out there for perl it just blows my mind....there is a module for anything you can think of.......anything.
I would say you cant go wrong learning C or C++ or Perl.
Good Luck.