Originally Posted by Banko
Depends on how multi-platform you want it to be.
However C# applications do run faster on Windows then Java, so Java 1.6 is a great speed improvement in my opinion.
I also like Java's Documentation better, and I think it is slightly cleaner.
Java's performance really ain't that bad anymore, especially once you tweak your jvm to get the garbage collector under some semblance of control.
C# ties you to windows and microsoft development tools.