C++0x is awesome !! i like it , easier to use !

Well, I've learned C, C++, PHP, Java and the easiest one is Java (and maybe PHP) once you got POO concepts

The first language I learned was TurboPascal, then c, java, zk(learning it again), php (self-taught), c#, c++, cobol, schemes (I hate schemes!)and prolog. I didn't get to learn assembly lang. yet. I wish I'm good with Java and .NET. They're so in demand right now (well in my country).

I started with Pascal, then moved to C++ then C. I would say the transition from pascal to C++ and C++ to C were both very easy. Pascal to C++ was like opening up an all new world of possibilities from what I could do with pascal, then everything I didn't completely understand in C++ was solved when I learned original C.

After that I learned general assembly which really helps with higher level languages when you know what's happening at the very low level. Then played with microcontrollers and FPGA's and learned VHDL, verilog (1000x easier and nicer to use than VHDL btw), and Atmel's version of C. Verilog and VHDL were a bit harder because you had to think more in parallel than sequentially. But it payed off when I started learning how to program in parallel using MPI.

Now I program things in parallel using MPI in C, sequentially with Java, and I really want to learn C# so I can play around with making some games in Microsoft's XNA program, but I probably won't get to that until the fall sometime.

I've mostly learned C and C++, with a bit of Matlab and G programming thrown in. I personally think programming is tedious haha but then you do get that sense of accomplishment once you get something working the way its supposed to. In any case, programming is basically just an implementation of a design. Whatever goal is needed gets filtered down to develop its requirements and functions and then is passed on to programmers to turn those goals into something that can actually be validated.

Well, as many here have said, it's the concepts in programming that matters, not the language.
Knowing how to program is a good thing since it might help you solve especially boring tasks faster.

I'd recommend at least one strongly typed language with C-like syntax (Java is easier to grasp than C, thus choose it ;) ). C-like syntax is common enough that you'd want to know it.
At least one OO language (Java is again a good choice). Object orientation is really good for solving some problems so you should know it and with experience, instinctively know when it's good to apply.
A scripting language, Python might be a good choice since it seems you're on the mathematic side of things and from what I've understood it's gaining popularity there as an alternative to MatLab.

Depending on what you wish to accomplish, a functional language might be good (I have yet to learn one though) since it is rather different from normal procedural programming. Since you already have some programming experience, it shouldn't be that hard to learn a new language. Much of what language you want to learn is connected to what you actually want to do, pick the right tool for the job. If you find it interesting and want deeper knowledge it might be good to actually take classes rather than teaching yourself, for instance introductory courses in algorithm theory and object oriented modelling teaches you good patterns to use and where to continue learning. Also such classes are much better than the pure "learn a programming language"-classes as those never tend to teach you the concepts, which is the important part.

I use C/C++ most, some time use C#/VB as UI developing.
Algorithm and software engineering concept is most important, language is just tool but nothing.
I suggest begin with a more modern and more simple language, like Java or C#.
if it's necessary, you can try to learn C++, it's useful if you need to access low level system(e.g. hardware/driver).
Modern software engineering won't work without OOP mechanism, if you're trying to become a programmer, you've better not to begin with old language without OOP mechanism, like FORTRAN or C.