There'd either be a [no-embed] tag you could wrap around the URL so that it still parses as a link, but doesn't embed... -OR- there would be an option within the post to "disable auto-embedding" (just like AME does it).
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.
Although... I personally think its a terrible idea. Its specifically why my XenMedio mod doesn't embed media directly into posts, but embeds an overlay trigger instead. When I was using a mod like this on my forums, we would end up with a single page with something like 30 youtube players embedded on the page... all these players, where you really only cared to watch 1 of them, or none of them still take up memory and resources on your computer.
It pretty much makes browsing on cell phones impossible.