User/Company Feature Ranking (Top 3/5/10)

I want a feature where each user or company can rank their top 3, 5, or 10 most important feature requests. This would help us identify the most critical needs for each customer automatically, reducing the manual work of asking them for their "top 5" list. It would be great if this could be defined in settings. The user suggested that a first step could be making custom fields editable by users after posting (which is already supported), but the core need is a dedicated ranking system.