I run my websites on a Windows Server. Years ago, when I started web development, I ran almost exclusively on LAMP (Linux, Apache, MySQL, PHP) setups, which worked great for the sites I was building.
As I got more involved in commercial development, most of the sites and services I was working on were C#, ASP, IIS and MSSQL Server focused. This is great for web development too.
When I moved onto a new, Windows based server, I decided that as I was running MSSQL Server and IIS on it, I would move my personal blog onto an ASP based platform - for this I chose BlogEngine.NET.
More than one year later, I've moved to WordPress if you're running sites that need some kind of content management system, it really is one of the best. With lots of support online, regular updates, plugins and themes, a WordPress site generally is easier to maintain and keep looking good than, for example, a BlogEngine .NET site.
I've also been very impressed with how easy it is to integrate WordPress into existing sites I'm updating my site http://www.childrenshomesnepal.org to have a news section driven by WordPress and it's a breeze - just a little bit of PHP and the posts are there.
The short message, so far I'm yet to see a better CMS than WordPress for day-to-day use. And that includes Drupal, which is powerful, but a bit of a nightmare to set up (and requires too much IT expertise from contributors to a site).