Adblock Plus

Though Adblock Plus for Chrome can block most Youtube video ads, it doesn't do a very good job blocking these sorts of ads on other video websites. And just for clarification, when I say "video ads", I'm either referring to the videos ads that play before the main video itself, or to the little banner ads that pop up within the main video while it's playing.

Adblock Plus for Firefox is still king when it comes to blocking video ads in general. If you're watching a video on (for example) Engadget, Adblock Plus on Firefox will block both the ads that play before the main video itself, and the small banner ads that pop up within the main video while it's playing. Neat.

However, on the Chrome version of Adblock Plus, these ads remain (sadly) unblocked. Adblock for Chrome, the main alternative to the Chrome version of Adblock Plus, also has these flaws with video-blocking. In this regard, neither of these two major Chrome adblockers do a very good job. For now, no matter which adblocker you're using on Google Chrome, you're still going to have to watch video ads. Shoot. :P

Adblock Plus: after FF4-installation ABP first was not compatible to Firefox 4
Without AdblockPlus It's hard to surf internet.
Solution: In the Addons tab, right-click AdblockPlus and use Find Update.

This is really the most useful addon ever.

@em4020: Xmarks is useful too, but in my opinion, nothing beats not seeing ads (is that a double negative?).

In the meantime I have added UnMHT to http://alternativeto.net/desktop/unmht/
I think, it is so important for daily use, that it shuold be found on http://alternativeto.net .
I agree with Xeogin, that Tab Mix Plus is also a very useful Firefox add-on:
https://addons.mozilla.org/en-US/firefox/addon/1122

"Adblock Plus" belongs to the 4 most necessary Firefox add-ons for daily use:
Xmarks (1), Adblock Plus (2), Add To Search Bar (3) and UnMHT (4).
(1) http://alternativeto.net/desktop/xmarks/
(2) http://alternativeto.net/desktop/adblock-plus/
(3) http://alternativeto.net/desktop/add-to-search-bar/
(4) https://addons.mozilla.org/en-US/firefox/addon/8051

The internet would fail without this add-in, it blocks ANYTHING. It's one of the few things that NEED to be open source, cause if not, companies could buy-out advertising space, like almost any other ad-blocker.