Hi DasFox, sorry you're having trouble with Flash, it's an issue thats the
subject of other threads here, and you'll find answers on those. They are
mainly workarounds using others players.
Probably the easiest way to get YouTube working is to install the
GreaseMonkey Firefox plugin, and the YouTube without Flash script. This will
work for most videos on YouTube. For ones that don't, they might run using
SwfDec, just click the "View Flash" link under the video. Others you might be
able to download with the download links. As far as I know, the rest are
currently not playable without Flash.
As regards web sites other than YouTube, some will work with SwfDec, or by
adding the web site to the GreaseMonkey script.
This issue should not occur at all. Everything to display the full
functionality of every web page should be built into the web browser.
Firefox Greasemonkey Extension:
https://addons.mozilla.org/en-US/firefox/addon/748
YouTube without Flash Script: http://userscripts.org/scripts/show/50771