YouTube Sidebar displays videos on a per post basis. To make good use of a single space it allows ads to be displayed when no video present
YouTube Plugins are nothing new but I like to add my own approach to every plugin. This plugin allows the insertion of a video ID for displaying with a specific post. The video is displayed instantly. This differs from plugins that may allow a single video to be added using an entire widget - not great use of a widget in my opinion. The YouTube widget management would become very busy if every widget was THAT basic. So the widgets in YouTube Sidebar will handle multiple videos and even ads when no videos are available.
If this still is not enough. Try my Video Blogger plugin which allows the display of videos from other streaming sites and offers other unique approaches to video management.
If you need a tool or an existing plugin customized. Please post it in this plugins forum and I will do my best to add the service to this plugin in the way you need it.