I didn't find any threads with this topic, but I'm sure it has been mentioned several times. I would really like XenForo to automatically recognize links to media sites such as YouTube and Vimeo (and other popular sites), so they will be embedded directly.
It's just not easy enough for people having to click the Media-button and then paste the link. This should be done automatically. The alternative is to be forever stuck with teaching new users about the need to use the Media-button for embedding.
In my former vBulletin-forum this was done elegantly through a plugin.
If there is such an add-on (which I have missed), please lead me in the right direction.