A nice to have screensaver is the Google Trends Screensaver. It shows a list of keywords that are trending in google, in a nice google colored screen. You can pick your country to show the most local trending words.
I made a hot corner in the left bottom to start the screensaver (and enabled the login after screensaver starts in security settings). So if I leave my macbook, I just move to the bottom left and the Google Trends start showing up (and my laptop is secured).
The screensaver can be downloaded here: