I've written code in almost everything under the sun and don't really give a damn one way or another. That said, choose Java. If you have to choose between C#

I've written code in almost everything under the sun and don't really give a damn one way or another. That said, choose Java. If you have to choose between C# and Java, go with Java because the JVM runs everywhere and the dotNet runtime runs only on Windows (excepting Mono). Go with Java. You can run everywhere there's a JVM and you have access to better libraries.