I have been struggling with this question a bit myself, although I have a lot of experience in the field. I started in 1983 learning languages that were then fairly modern. I learned assembly, C, Pascal, FORTRAN, and others. Since graduating in 1985, I have picked up C++, PHP, Python, SQL, and more. My contract work today is in a "Fourth Generation Language", PowerHouse which is essentially obsolete. Nothing approaches Powerhouse for productivity, in my experience.
That said, the most important new languages, for me are PHP, Javascript, and also SQL, which is 'ancient'. SQL is the odd one here while the other two are similar enough to C that they can be though of as a group, for learning purposes.
PHP is the language used by WordPress. That platform is extremely important due to its popularity. With some PHP knowledge, you can build plugins to improve your site's functionality. You may even have a market for your plugin.
SQL is a different type of language but it is practically vital to understand. Anyone could learn the basics in a day.
"Select Name,address,phone from Customer_table where status="ACTIVE" order by Name". This does what you think it would, but it's not pretty:
Bill box 100 555-1212
Carol 123 Main St 555-1291
Zeb 400 Elm 555-2912

My take on object oriented, "OO", programming is that you should know a lot about programming before you bother with it. My favorite quote about OO is that "we use it because we have it". It can make programming more efficient by saving typing time, but it can be avoided through the use of structured design. That is the concept where you build a library of functions that perform standardized work for you. We used to do this all the time with C and other languages. We still do it with PHP and other OO languages, even when objects are used. I think that OO makes some aspects of maintenance programming harder because you need to track down issues differently. I would be willing to be entertain comments on this.
To me, the best language to use now is one that fits your need. If you are working with WordPress, then PHP could be important. Add in Javascript, and even HTML, to round out your skills here.
Almost the entire technical world runs on SQL now. Even many programmers don't know it. It's great to know the basics, and more, so that you understand how things are working. If you have to code business systems using old legacy languages, (like I do), then SQL is vital, (and well paying).
I like the idea of a modern language comparison matrix. I should write one and see what comments come in from others.

I don't have a tremendous amount of experience in programming, but if you're looking for an OO language to learn that's pretty flexible, you could check out Python or Ruby. Personally I've almost exclusively used Python since learning programming, and it's a very sleek, powerful language. Very popular as well! It all depends on your primary intentions with programming and what you're using the language for obviously.

As javrsmith said, PHP is pretty much the web development, market "standard" for web development (unfortunately, in my opinion) due to wordpress. If that's something that concerns you.

This would be really cool, and I could learn a lot from it too.

Even with C you can write CMS.

It look like you don't have enough experience - languages and IDEs are just tools. Different tasks require different tools, it is just not time effective to write CMS on C. Support will be way to costly.

First you have to define for yourself which kind of applications you want to write. C# isn't effective for server side apps, because there are no enough libs and "tune-up" tools for this task.

It depends on what you need. There are 3 major languages in terms of web programming.

1. High end: Java and Oracle database (For big companies)
2. Middle end: C#/ASP.NET and SQL Server. (For middle or small companies)
3. Low end: PHP and MySQL. (For small companies or personal websites.)

If you do mobile programming, that's anothe story...

Best comparison are "TOP used" lists.

Go to sourceforge or github and check which is most used language. Then learn 1 or 2 of them, that will cover most of your tasks.

From my experience and from what others have told me (programmers), the best thing to do is to learn the basics. Which means learning C#, or something similar but from the C family. It's not mandatory, but many say that helped them a lot, in terms of understanding how programming works.
And, after that, you can go ahead and learn the programming language you need, depending on what you will use your knowledge for.
For instance, say you're looking to get hired by a company, you would need to know which position you need to apply to. Gamefan summed it up just about right, each programming language is good for something, but learning just one that does everything is probably not possible.

I like the free languages justbasic.com and Quincy C/C++ at Quincy: Simple free C/C++ programming IDE for Windows

These are simple freeware development languages that you can use for anything, but they're great for learning. Justbasic may be a little easier but basic is a little strange compared to C/C++/PHP, etc.

high level language is a programming language with strong abstraction from computer.
1. C:It is the mostly used for developing low level applications as it is consider nearest to the hardware.
2. C++:C++ language was develope in 1983 which is often consider as the object oriented version of the C language.
3. Java: This language support lots of features and capabilities of C and C++. The additional thing in java is that it is pure object oriented language.
4.C#:C# belong to the microsoft family programming language. It combine the robustness of c++ and advance feature of Java.
5.Php: It is most widely used programming language for developing dynamic website.
6.javascript: Javascript is a server side language for developing complex web application.

App development language
PHP
node.js
Java

It all depends on what you want to develop. For UNIX, C helped a lot - for the Internet, PHP, HTML, JavaScript, MySQL is perfect. for Windows apps Visual Basic (don't give me crap) is the easiest.

I learned a lot of programming languages in college and do not use all of them today. I think it's good to be exposed to all of the other programming languages.

So to break it down, it all depends on what you want to do. Yes, it's nice to master one. But learning the other languages doesn't mean you can't master those as well. As you will discover, one language compliments the other.

Hope this helps,

I think there is no BEST language. There are languages suitable for your needs, or languages that suit you, as a programmer.

Chose one language that suits you and your needs and go with it.
Like, PHP, Ruby, Python, they're used in web development, java is used in android development etc etc

In my point of view java and c programming languages are evergreen one!!!

Java,C and C++ languages are good for app development