For someone who’s been happily programming in C# for quite some time now and planning to learn a new language I find the Python community more closely knit than many others.  
Personally dynamic typing puts me off, but I am fascinated by the way the Python community rallies around it. There are a lot of other things I expect I would miss in Python (LINQ, expression trees, etc.)  
What are the good things about Python that developers love? Stuff that’ll excite me more than C#.
Like any programming language, it is just a tool in the box or a brush by which you may paint your creation.  Any creative endeavour requires that the artist loves the tools he uses; otherwise, the outcome suffers.  Some people like Python for the same reason others love Perl. Incidentally, I have found that most Python lovers loathe Perl's flexible and expressive syntax. As a Perl lover, I don't hate Python, but consider it to be overly structured and restrictive.
If you ask me, all of these throngs of people who seem to love Python were silently suffering under the tool choices before Python came into being. Some suffered under Perl, others under something else.  In other words, I believe that when Python came along, it found a large group of silent sufferers longing for a tool like Python.  
I can't program in Python because I can't "think" in Python. I can "think" in Perl, therefore, it is the tool I prefer. The silently suffering mass of, now, Python users seem to have found some long lost salvation. Now if they could only keep their evangelism to themselves :).
What Python features will excite the interest of a C# developer?