These are my favourite Google Chrome extensions at the moment.
Basically what Ghostery does is it detects trackers, web bugs, pixels, and beacons placed on web pages by Facebook, Google Analytics, and over 500 other ad networks and blocks them.
ScriptNo is very much like the famous NoScript for Firefox. In my opinion, it is the best plugin of that kind for Google Chrome.
The best way to block ads.
If you often watch Youtube videos, you should get this extension.
This will block all the annoying pop up windows.