There's no "base language", you can go with any language you want. If you want to make some games, you'd better off learning C++, but if you're into fancy, myriad database applications or anyhting that's to do with windows GUI (which is practically everything but games), you might want to try Delphi or Visual Basic. If you want portability and/or programs/games for the internet, Java is the way to go. Of course you can do "normal" applications with C++ as well, and it might be good to learn C++ since it's so popular and widely used and it's easy to find free compilers for any platform. DO NOT bother learning C! Zero knowledge of C is enough if you want to learn C++.
Hope this helps!
Just wanted to add a few things...VB/Delphi are visual development tools (I think there's some fancy name for them, but can't remember), which means that you can actually have a form (=window) and drag components like buttons, textboxes and so on on it, and for each component you can write a piece of code (e.g. when pressing button 1 do this and that...) <<that's a very crude explanation but I hope it'll do. C/C++ are..."purely text based" (you write all the code by yourself) and creating user interfaces like windows and such is vey, VERY hard.
BTW DirectX APIs come for C++, and C++ programs compile into very effective(=fast) code and you practically must know C++ if you want to be a games developer.
