You may use Adblock Plus which doesn't requires the phone to be rooted. It also respects your view:
I use a lot of free apps, and understand that ads are an essential part of making sure the maker gets paid.
You can opt-in for this:
What are Acceptable Ads?
Many people use Adblock Plus to block annoying ads. However, we don't think that all ads are bad, and we are fully aware that they finance many websites. Therefore we have established strict criteria to identify Acceptable Ads: unobtrusive ones that don't need to be blocked. Websites that are willing to comply with these criteria can apply to have their ads added to the Acceptable Ads exception list, which will unblock them for all users that decided to keep Acceptable Ads enabled. Note that if you don't want to see any ads, you will always be able to opt out of this.
Please see the Acceptable Ads FAQ to learn more. (Source)
What is Adblock Plus?
Adblock Plus lets you block annoying ads, tracking, malware and other things you may not want in your browser. Adblock Plus is an open source project created by Wladimir Palant in 2006. Eyeo was founded in 2011 by Wladimir Palant and Till Faida to make its development sustainable. [More Info]
Note: When I used this app a year ago, it had problem with blocking ads on Mobile Data and worked only on Wifi. Please update this answer if it works with Mobile Data now. Also, once installed, disabling it and trying to use browser resulted in no internet connection in any web browser. It is possible that these issues may have been get ridden of by the subsequent updates.