UjW0L

This plugin lets you to display Youtube widget on sidebar with the themes that supports sidebar and Footer
It displays video and playlist of your choice with video id and playlist id. 
It also lets you display all videos from you youtube channel with option to navigate to next nd previous button. 
No google API key needed. Uses Youtube rss feed.
You have choice between single video , playlist and channel.
Note:

Simple Youtube Widget

Plugin that provides users option to display Youtube Widget on the Sidebar or Footer

Mahabubur Rahman

The pluging for embed youtube video using youtube video id.
<h4>Features</h4>
<ul>
<li>Add a video to your wordpress site widget area.</li>
</ul>

SM YouTube Video iFrame

The pluging for embed youtube video using youtube video id.

Simple Youtube Widget vs SM YouTube Video iFrame