Java! Why it's good to know

[fgh367]

Biggest advantage of all in my opinion are the loads of libraries.

[eulalies]

is java better then c#?

[HaXzz]

is java better then c#?

This question really falls upon ones opinion.
I typically code cross platform applications in C++ or Java because they can be run on all systems while C# (as in the coding language) cannot. 
Also @bitm0de has pointed out to me that .Net which most c# applications are built on is actually cross platform.