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.

Thomas

Responsive Embed Videos allows you to easily add youtube or vimeo videos to your website using our shortcode like :
[rev video=’http://youtube.com/watch?v=whatever’] or [rev video=’http://vimeo.com/whatever’]
All videos embeded with this shortcode will be fully responsive.
Here is a list of the shortcode attributes :
video – default: none | This is the url of your video, from youtube or vimeo only for now.
width – default: 100% | This is the width ( in % ) of the player.
align – default: center, left, right | The horizontal alignment of the video.
ratio – default: 16/9 | This is the ratio we use to resize the player.
style – default: simple, normal | This is the style of the player.
Languages: English.
Disclaimer :
I can’t guarantee a 100% compatibility with advanced themes who may already make the embed videos responsive or with other video plugins.

Responsive Embed Videos

This plugins makes your embed videos included with its shortcode responsive. Compatible with Youtube and Vimeo.

Simple YouTube Responsive vs Responsive Embed Videos