I've just re-added the Youtube plugin to the forum so when you paste a youtube video into a post, it automatically displays the player
To add your own videos to posts, you don't need to do anything clever. Simply paste the URL into your post - it doesn't need any extra URL or hyperlink code!
e.g. (make sure you use http in the link, i've just put * in to show the code in this post
And you get: