> Apparently C# has a pretty comprehensive standard library but I've never used it.

I use C# more days than not. The comprehensive standard lib is impressively large and accomplished everything I need. Third-party libraries is a real pain point though. I haven't looked in sometime, but things like sane PDF libraries, reporting libraries, etc. were severely lacking when I needed them last. As much disdain as I have for Java, I think it is better in that regard.