Eirudo

<p>A lightweight plugin to embed YouTube videos while keeping the correct aspect ratio — all with a simple shortcode.</p>
<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>
<p>Pros:<br />
1. Simple and lightweight — one shortcode per video<br />
2. Lazy load support<br />
3. Extra parameters available for advanced users</p>
<p>Cons:<br />
1. Designed for simple embeds only (no playlist support, one video per shortcode)</p>


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.

Roi Dayan

<p>Simple youtube plugin to help embed youtube videos.</p>
<p>Support for playlist by time (jump to specific time in the video).</p>
<p>playlist css is from flowplayer playlist plugin.</p>


Simple YouTube

Simple youtube plugin to help embed youtube videos with playlist by time.

Simple YouTube Responsive vs Simple YouTube