Configuring the humanarchy forum I found out that the media tag displays videos better than the youtube tag. It will embed youtube as well as vimeo and dailymotion as well as a list of others I don’t know, and then also things like souncloud and google maps.
The main advantage is that it embeds youtube videos in their actual ratio, meaning frequently 16/9 instead of 4/3 with black bars, which is what you get with the youtube tag.