If you use Google Reader, you can try the Explore link that is above your own subscriptions.
In the left-hand Explore section, you'll find Recommended items and
Recommended sources. We use algorithms to find fresh and rising
images, videos and pages from anywhere on the internet to generate the
Popular items, and then rank them in the order we think you'll like
them.
The articles that Google recommends generally have a high number of +1s
Your recommendations list is automatically generated - it takes into
account your existing feed subscriptions. Aggregated across many
users, this information can indicate which feeds are popular among
people with similar interests