After removing a large number of Google Chrome extensions I really didn't need, I was left with the following 4 essentials. Each of them save me time and effort when browsing (and submitting the occasional web post).
If I see a sponsored link to something that sparks my interest I always click it, particularly if I have landed on the page and found something useful. I do however take exception to flash and other animated effects that distract me from reading or poorly marketed advertisements that have almost nothing to do with the page content. Generally these are on pages that will get few revisits from me in any case. Mostly I keep this extension around out of habit I guess.
Context Menu Search
I have been using some form of context search in Firefox and Chrome for nearly 10 years now. I have become very accustomed to defining words, locating online videos and so on, in this manner. My only requirement is that the menu remains refined and search functions can be added easily. The last extension I used Context Search (a different extension) achieved this but I was never comfortable with the user interface. So I am trying Context Menu Search instead which integrates properly with the existing browser context menu: as I think it should.
I am still assessing this extension. It adds some features to Google Plus that I require: most importantly customizing my stream. There is also a feature to adjust the layout to make better use of view able space. So far it is proving to be worthwhile.
This extension is a time-saver when authoring weblog posts as it provides access to a url shortener, posting interface and sharing tools all from one drop-down menu. The dev team appear to be working to add support for google plus which will be helpful.