I currently run Ghostery alongside Disconnect and Facebook Disconnect Chrome extensions, mainly because I'm not sure how their feature set overlaps. Do the latter two offer anything that isn't already included within Ghostery's fuller feature set? Is there a better Chrome extension than Ghostery for my purposes?
Ghostery and Disconnect act as content blockers (if you've enabled blocking) and their innards are very similar. Heres an answer I provided recently on Ghostery support board:
This question is asked pretty often on our support boards (I work for Ghostery). You can use however many addons you want in conjunction, however, both DNTMes and Disconnects databases are a lot smaller than Ghostery internal tracker database. We've setup an automated efficacy tool here: http://www.areweprivateyet.com/ to measure how well the extensions are doing on their own.
An additional note is that Disconnect number is for the number of requests while Ghostery and DNTMe use the number to show you how many companies are present on the page. So, lets say a web page has 3 calls to Google Analytics, Disconnect will show 3 as its number, while DNTMe and Ghostery will show only 1 -- Ghostery however, will show you all 3 sources if you open the reporting panel and expand the sources of Google Analytics.
Outside of that Ghostery offers a bunch of features that Disconnect does not at this point. They are: click-2-play overlays (for when you wonder where your comments and videos may have went), surrogates (when Ghostery blocks a tracker, it can provide a dummy script that replaces previous one so sites do not break), knowledge pages (so you can learn about the trackers), and much more.
AFAIK, Disconnect replaces Facebook Disconnect, however, if you only want to block Facebook, you're better off with just Facebook Disconnect.