Perhaps something like http://feedafever.com/ http://feedafever.com/ is what you are looking for. From the site: While It’s Hot Fever reads your feeds and pick

Perhaps something like http://feedafever.com/ http://feedafever.com/ is what you are looking for. From the site: While It’s Hot Fever reads your feeds and picks out the most frequently talked about links from a customizable time period. Unlike traditional aggregators, Fever works better the more feeds you follow.