I've written PHP web projects for several years and considered myself intermediate with PHP. I recently wrote an application (in PHP) for a company that got noticed by the programming department, and they had me transition to a job programming in C# and .NET.
My first reaction was very standoffish; I learned to program in an anti-Microsoft environment and mindset. The last thing I wanted to do was learn something in .NET.
After several months of forcing myself to learn C# and OOP I have to say it's actually a wonderful thing. At least for developing Windows applications. I'd always wanted to do some desktop applications and this has been a great way to do it.
But so far nothing has involved ASP.net, and now I have a project which requires some web output. I'm struggling with learning ASP, and the fact of the matter is I am tempted to write the web portion of it in PHP. For me, C# makes sense for Windows and OOP, but for quick data-parsing applications on the web, PHP is quick and gets the job done.
I am going to keep working on the ASP thing though, specifically looking at MVC. Another question on SO got me interested in focusing on MVC. I've been perusing books and watching tutorial videos, and so far I am hopelessly confused.
Perhaps it will be something I look back on and am grateful for having made the effort -- like learning C# in the first place. Right now, the ASP approach to web coding seems foreign, despite knowing more about C# and OOP than I did a year ago.