The ability to create a List View.
One use would be to graphically represent the hierarchical structuring of records, e.g. Tasks and Subtasks.
A feature of List View could include the ability to replace Field names with icons - even user-defined icons (by pasting in a PNG, etc.). Hovering over the icon would reveal the Field name and perhaps other controls - like in the case of Time Logging.
This would help to get as many fields as possible onto a single screen without needing to horizontal scroll. (Perhaps icons could be incorporated into other views as well - Kanban View, Grid View, Gantt View) ;)