ROFL @ 4wd.
I just had to do it
No offense to the original poster but it really is a rather vague question to ask.
The equivalent of: "What's the best software for writing CD/DVDs?".
Only a hundred times worse.
There are so many factors that come into the equation that without supplying a lot
more information the only valid answer is: The language that you feel comfortable with and that allows you to do what you want with the minimum of effort.
The software development equivalent of K.I.S.S.w
No need to learn the complexity of C#/JAVA/Assembler/etc if you only want to create small apps of use only to yourself for doing something really esoteric when using AutoIt/BASIC/etc will get it done in far less time.
However, if it's knowledge that you want to put to use throughout the rest of your life, then yes, learning a Object Oriented, platform independent language is going to be more useful in the long run.