ASP.NET MVC View Model Naming Conventions

It doesn't matter. You should name things in a consistent, logical, and straightforward way. Basically, just pick something that makes sense and makes you most productive. Consider how your naming convention would work with IntelliSense.

You might also want to consider how easy your code will be to maintain a year from now.

I prefer like {ViewName}{Controller}ViewModel. I also remove Models folder, instead I put view models in ViewModels folder. That makes more sense to me.

eg. AddCategoryViewModel