xmarks.com seems to be a good website to explore more based on what you already like. It also helps its visitors find similar websites and seems to be providing good results for popular websites. I tried searching similarsites.net here and results were not perfect but were not disappounting as well. You can find more interesting websites that are similar to xmarks.com at the following location.

 http://www.similarsites.net/Site-xmarks.com.aspx

Looking for your reviews about this website and how do you rate it in comparision with similarsites.net.