In case you haven't guessed by now my preferred language for general tasks is Python. For general desktop/console apps I will use either Python or IronPython (I like System.Windows.Forms). For AutoCAD .NET extensions I use Boo exclusively but would consider VB.NET over C# if I were forced to use a MS provided .NET language.
I actually agree with you about Python and Boo. I actually wish that C# had taken more from Python, but I would hardly call it a "horrid" language to deal with.
Personally, I've never liked VB, and do not view it's lack of curly braces as a redeeming feature for the rest of the syntax. I'm surprised that you would say you would prefer VB over C# for such a minor reason. But to each his own.
As far as using Boo, the problem there is that it is still a young and relatively unknown and unsupported language. Sure, it's got its core of rabid followers, and it is powerful and has major potential, but it is not a mainstream language at this point. And any time you choose to use a language that is not mainstream, you have to deal with additional complications, and have more-difficulty in using that language in a large development effort. And you always run the risk that the language will NOT end up being a mainstream language at all - it may instead merely be the precursor for a not-yet-invented language that becomes the mainstream language.
For example, 15-20 years ago, there was a big debate about which one to use, C++ or Objective-C. C++ was by-far the nastier of the two, but for various reasons we don't need to get into, it "won". However, the entire crop of current languages - Java, C#, Python, and even Boo - took many of the ideas and principles straight from Objective-C, and all these new languages are far more like Objective-C than they are like C++. (And to be fair, Obj-C stole many of those principles from an even-earlier language - Smalltalk.)
So although I agree with you that Boo is a "nicer" language, and undoubtedly a "better" language, I still do not agree with you that C# is "horrid". By contrast, it is remarkably close to where Boo is at. Boo is better in many respects, but C# is surprisingly clean, considering it was a Microsoft effort. By contrast, take a look at C++, and then you'll see a REAL example of a "horrid" language.
And of course, it is difficult right now to get any more "mainstream" than C#, at least if you are working on Windows. That is a significant advantage.