Adblock Plus is a Firefox add-on that makes ads disappear (and has plenty of other useful features, too).
Just install the tool, restart Firefox and it'll begin filtering your web pages immediately. Most, if not all of those annoying Flash ads will disappear right away, speeding up your browsing and allowing you to concentrate on the site content.
The program hasn't worked for you? Adblock Plus provides a choice of more than 40 filters, and you can choose the ones that are most effective for you.
There are filters for many languages beyond just English, for instance, from Dutch, French and German, to Chinese, Vietnamese, Japanese, and more.
And you can also install filters for many specific purposes: to block ads on adult or P2P websites, to protect you from privacy risks, keep you safe from known malware domains, and even a blacklist for known Rickrolling pages (no, really...).
What's new in 3.2 (see Release Notes for more):
- Added the $rewrite filter option (issue 6592 and issue 6622).
- Blocked elements are now hidden through a style sheet if possible rather than by overriding their style attribute (issue 6645).
- Stopped converting domains reported by the browser to Unicode, expecting domains in filters being given in Punycode (issue 6647).
- Fixed: Requests were matched in the wrong context when navigating to a document served by a Service Worker (issue 6595).
- Fixed a regression introduced with the previous release that caused the number in the icon badge to show even if that feature was disabled (issue 6679).
- Added information about filter hits and related requests to issue reports (issue 6386).
- Removed the title field when adding a subscription by URL (issue 6532).
- Formatted dates on the options page based on the current locale (issue 6661).