As you probably heard the Windows Uservoice Forum will be shoutdown on November 16. In the meantime it will be still accessible, though the voting and comments are disabled.
Microsoft advice us to use the Feedback App instead. The tricky issue with it is that its kinda localised based on your keyboard language so if you want to see the gross of the suggestions you should first switch your keyboard language to English US. Also make sure "My build", "My Feedback"or other sorting option are not checked.
Ive found some interesting suggestions for both functionality and design that I think most of members of this group would agree with and vote upon. Ive even submited my own ones (those marked with the *).
Some are very popular but some are not, some are old, others recent so you may not find them instantly using the search box and you might need to scroll. They should be searched in the specified category/subcategory using the