I can't speak on C# vs Python or C# vs. Lisp, since I haven't coded in either of those languages. I can speak on C# vs. php - I just finished a job with php and started C#. Originally,I thought I loved it because of the library (ie dataset, dataview,gridview), and garbage collection. Then the object orientedness of it all got really, really hard to implement rapidly. I may still use it to write sockets and hwnd stuff for windows (I'm a game dev), but for web stuff, I'll stick with php and maybe learn py.