Diigo has been my go-to ever since delicio.us folded. You can add any number of tags to each link, and the tags are easily searchable. The interface is not clut

Diigo has been my go-to ever since delicio.us folded. You can add any number of tags to each link, and the tags are easily searchable. The interface is not cluttered by enormous graphics, so you can view a large number of items on each page. The browser plugin and mobile app are also rock solid. Whenever I want to save a article for reading, I add the tag "readqueue", and next time I want to read something interesting, I just search for that tag. When I finish the article, I change the tag to "readDONEqueue". I also have a "watchqueue" for videos. I use it so much that I even signed up for the paid plan - it's been incredibly useful and has saved me from bookmark hell these past five years.