Whenever I talk in non-technical terms to someone in comparing web forms with windows forms apps I always use Quicken as an example of the rich client UI of windows forms. This is an excellent example windows forms-LIKE application (I know its not .NET), particularly when comparing paying bills using Quicken with using an online web-based bill paying service. No comparison!
Tonight I used Intuit TurboTax for the first time to prepare our federal and state taxes. After using CPA firms for the last decade, my wife and I decided to do our taxes ourselves this year. Now I can add TurboTax to the list of great examples of Windows Forms-like applications. Great navigation features, importing capabilities, printing, efiling, etc. I particularly was impressed by how logically intelligent TurboTax is in asking questions and moving you through the process based on your answers.
Very positive experience (until I got to the end :-)