It would be great to be able to add Sections to Lists.
This could also be thought of as grouping certain tasks within lists.
Sometimes you want tasks to be in one list, but also be able to group them/put them in to sections, so you can better chunk them.
For example, I make films, and I would like a list for a film to be able to be grouped in to "Development", "Pre-Production", "Production", "Post Production", "Release".
It isn't suitable in this instance for me to make each film have its own project and then make individual lists, because I group film types as projects. For instance, I have a Project "Short Films", then each short film is a list. It would not work having a Project for each film, as the project list would be huge.
This is something that can be done in Asana, and is very useful.