geilt

Enables a widget that will pull a youtube feed via JSON by Youtube Username/UserID or PlaylistID and display text and/or video preview images. Supports images thumbnails, image thumbnail galleries (as slider) and more. Does not play videos on your site, only links out.
<a href="http://www.esotech.org/plugins/simpul/simpul-youtube/" rel="nofollow ugc">More Details</a>

Simpul Youtube by Esotech

Enables a widget that will pull a youtube feed via JSON by Youtube Username/UserID or PlaylistID and display text and/or video preview images.

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

Simpul Youtube by Esotech vs Simple Youtube Widget