specimen

WP Latest Video Widget is a sidebar widget that displays latest video from a custom set category. Based on custom fields.
What’s new
<ul>
<li>Added Romanian localization.</li>
<li>Widget title now can link to post containing the video.</li>
<li>Widget title now can link to category containing the video post.</li>
<li>Widget title now can link to site containing the video.</li>
<li>Fixed various bugs.</li>
</ul>
Supported Sites:
<ul>
<li>YouTube.com</li>
<li>Vimeo.com</li>
<li>Apropo.ro/Tare.ro</li>
<li>More to come!</li>
</ul>

WP Latest Video Widget

WP Latest Video Widget is a sidebar widget that displays latest video from a custom set category. Based on custom fields.

Eirudo

Embed YouTube videos and keept their aspect ratio, just using simple shortcode.
<ul>
<li>Simple shortcode, can be used in the posts or widgets.</li>
<li>Using default YouTube Embed Code (iframe), but make it responsive</li>
<li>Custom aspect ratio, if you want set different porpotion size.</li>
<li>Auto centered position. So if you insert it on your post section, the video always on center-aligned.</li>
<li>Lazy Load supported.</li>
<li>100% Free! And no ads or even trackers inside.</li>
</ul>
<h3>Arbitrary section</h3>
<h3>A brief Markdown Example</h3>
Pros: 
1. Simple, only using shortcode to use for individual video each shortcode 
2. Lazy Load supported 
3. Custom parameters for advanced use
Cons: 
1. Only for simple use,not for advanced playlist. Embedding one video for each shortcode.

Simple YouTube Responsive

Perfect

You can add a line to your functions.php to make videos responsive if you're doing your own theme. However, if you're not, this plugin works beautifully and gives other options like lazy load, etc. 

If doing your own theme, add: add_theme_support( 'responsive-embeds' );

Works Beautifully

Embed responsive YouTube videos using simple shortcode. Lazy Load supported.

WP Latest Video Widget vs Simple YouTube Responsive