Which one is better and why ? Php or Asp.net

Answer 1

its up to you..
better you chose which one you know better.. because it will help you to build a program which you can control it..
just like @netkos, I know php better than ASP. net, so I use php too.

Answer 2

You'll get mixed opinions on this. Play around with both and use whichever one feels best to you. I prefer PHP because I know it better than ASP.net, but ASP.net is really good also.