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

A lightweight plugin to embed YouTube videos while keeping the correct aspect ratio — all with a simple shortcode.
<ul>
<li>Very simple shortcode. Use it in posts or widgets.</li>
<li>Uses the default YouTube iframe embed, but fully responsive.</li>
<li>Custom aspect ratio if you want a different video size.</li>
<li>Automatically centered, so your video always looks neat in your content.</li>
<li>Lazy load support to improve performance.</li>
<li>100% free — no ads, no trackers, no funny business.</li>
</ul>
<h3>Arbitrary section</h3>
<h3>A brief Markdown Example</h3>
Pros: 
1. Simple and lightweight — one shortcode per video 
2. Lazy load support 
3. Extra parameters available for advanced users
Cons: 
1. Designed for simple embeds only (no playlist support, one video per 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

Easily embed responsive YouTube videos using a simple shortcode. Lazy load included.

WP Latest Video Widget vs Simple YouTube Responsive