When I'm coding in Java, I generally just use TextWrangler (on OSX) or kate (on linux) as my editor, and commandline tools like ant and git to manage everything else.

I think C# needs an IDE like VS more than Java, if only because it doesn't have a standardized high-quality documentation tool equivalent to javadoc. For many .Net libraries, intellisense is the only source of documentation, and MSDN docs are rarely very helpful.