I use WPF
I am a big fan of WPF and I use it when ever I can. I love XAML and I love data binding. The MVVM design pattern really helps in creating a decoupled, maintainable product.
As I work on my Masters of Computer Science, I do my homework with full WPF and Binding using MVVM because it is fast and clean. If I take time to open it in Expression Blend and work on the WPF Design, it looks good too.
Check out my latest Unit Test project over on my other blog. I of course wrote it in WPF using Binding and MVVM.