Chrome Extension: Chime
Cycling through your favorite websites on a day-to-day basis may be fun, but sometimes you just want any new interactions to come directly to you all in one place. Chime does that.
You can see your past notifications by hitting Chime's button at the top, and the clicking All Notifications. This page also allows you to set up each website for the first time and sort through each website's happenings by clicking through the square icons. If the icon is brightly colored, it's enabled in the main list. If it's dull, it's not going to show you that website's notifications. Simple and effective.
It also has unobtrusive desktop notifications which show up even while you're not in Chrome (unless you disable that feature by unchecking a box). If you don't want to see any notifications pop up (and the Chrome icon greyed), simply press Do Not Disturb.
Chime has support for the top 3 social networks including Facebook, Twitter, and Google Plus; but it has support for a few others too: Gmail, Reddit, LinkedIn, Flickr, Quora, Foursquare, Github, and Stackoverflow. You can find it in the Chrome Web Store.