One of the best add-ons Rated 5 out of 5 stars

Very effective add-on and quite easy to use. Making your own blocking rules may be a bit challenging for some people, but luckily the lists you can subscribe to basically blocks everything. It's also nice that you can white-list domain/pages you trust, to support them with ad revenue.
The recent move to allow non-intrusive ads may have angered some, and I guess it could end badly, but for now I think it's a great way to put pressure on the ad companies to make ads that follow user-friendly guidelines. Should you disagree, you can still choose to block everything.

This review is for a previous version of the add-on (2.0.3.1-signed).