1. If you use Safari on your Mac,
I suggest you use AdBlock (this is not AdBlock Plus)
It will also work in Chrome and Firefox. While AdBlock is free, it is the labor of love of a US-based husband and wife team. Maintaining it is their job and they employ others on their team. Give them a donation every year if you like it.
2. If you only use Chrome or Firefox, I suggest you consider uBlock Origin, developed by Raymond Hill. (uBlock Origin is not the same as uBlock.) Raymond develops his extension based on principle. It is an act of charity. He does not accept donations or charge for his software.
uBlock Origin for Firefox
You can also install AdBlock for Chrome or Firefox.
3. iOS (iPhone, iPad, iPod Touch) — fall 2013 and later models. This would include — iPhone 5s and later, iPad Air and later, and the most recent (2015) iPod Touch.
After rocketing to #1, the Peace ad blocker is no longer with us. The developer pulled the app for business reasons; all customers were given a refund. Shortly after, Crystal shot up to #1 on the App Store. Sadly, they sold out to Ad Block Plus. Therefore, for iOs The Acronym is recommending either
(Free for basic ad blocking, $3 for all security features + web based management)
(regularly $3, on sale for $1)