There are various search extensions released officially by Google to provide more easy and fast web search experience on Google Chrome.
Personal Blocklist (by Google)
With this extension you can keep certain domains out from your search results page. It will transmit to Google the patterns that you choose to block.
Google Similar Pages
Using this extension you can discover webpages similar to the page you’re currently browsing. This way you can find more pageson the topic you’re researching.
Search by Image (by Google)
Allows you to initiate a Google search using any image on the web.
Highlight to Search
Enables you to search keywords simply by highlighting instead of typing them into a search box. Also pops a search-box with auto complete suggestions.
Google Quick Scroll
You can jump directly to the relevant bits of a Google search result. As you click on a Google search result, Quick Scroll may appear on the bottom-right corner of your page, showing bits of text from the page that are relevant to your search query. Clicking the text will take you to that part of the web page.