ASP.NET or PHP?

I want to get into web programming, but I'm not really sure what server-scripting language to get into. I've read good and bad things about both, but I like the fact that ASP.NET will allow me to use C#. I know the basics of HTML, CSS, and JavaScript, they're all fairly straightforward and simple. What advantages does PHP have over ASP.NET and vice versa? I'd like to get advice from someone that's used at least one. All I'm really aiming to do is to make my own website, and learn a bit about how web servers work. I can see that most programming jobs and tech in general is moving more and more towards web/cloud, so I'd really like to learn about it. Anyone have any unbiased advice coming from their experience?

php is very easy to learn

Well, I know quite a bit about HTML, CSS, Javascript, and a few other languages, just no server scripting languages. After some reading though, I think I'm gonna try ASP.NET. Code-behind seems awesome. After I'm familiar with it I'll try PHP. Question: Can IIS run PHP? If so, is it any good, and can a server run PHP alongside ASP.NET?

I personally prefer PHP. It has much greater support and is cross-platform.
C# *should* be able to be used as a cgi script however do not quote me on this. I have made C++ cgi scripts - dont know specifically about C#.
ASP.NET is Microsoft proprietory and therefore I don't like it. It will not work on linux (unless maybe under WINE).