uBlock

µBlock is not (just) an ad blocker; it's a general-purpose blocker. µBlock blocks ads through its support of the Adblock Plus filter syntax. µBlock extends the syntax and is designed to work with custom rules and filters.

Ads, "unintrusive" or not, are just the visible portions of privacy-invading apparatus entering your browser when you visit most sites nowadays. µBlock's main goal is to help users neutralize such privacy-invading apparatus — in a way that welcomes those users who don't wish to use more technical, involved means (such as µMatrix).

EasyList, Peter Lowe's Adservers, EasyPrivacy are enabled by default when you install µBlock. Many more lists are readily available to block trackers, analytics, and more. Hosts files are also supported.

To benefit from µBlock's higher efficiency, it's advised that you don't use other inefficient blockers at the same time (such as AdBlock or Adblock Plus). µBlock will do as well or better than most popular ad blockers.