C# - Adding Arbitrary Properties To A Strongly Typed List?

I'm looking for a good way to add arbitrary properties to the objects in a strongly typed list, based on the principle that I shouldn't pass a DataTable from my business layer to my presentation layer.For example, I might have a Category class with the properties CategoryId and Title. On one page I would like to fetch a list of all categories (ie. List<Category>) together with the most expensive product in each category.A while ago, I would have just returned a DataTable with some additional columns in it with the product data in, but I'm trying not to do that -- it would be trivial to set up it's not good practice. One option is to add a MostExpensiveProduct property to my Category class, but I might want to display the most recently added product in another case, or the cheapest product, so I'd end up adding a lot of properties to cover all the options. This just doesn't feel right to me.Am I missing a trick here? What is the best way of doing this? Or should I just be returning a DataTable to which I can add as many columns as I need and not worry about it?