xundeenergie

Gives you a shortcode for Youtube-Videos and makes a preview-pic for this Video and realizes to watch the video with fancybox for wordpress oder prettyPhoto or in a extra tab. You choose, what you want.
The URL ist for example: http://www.youtube.com/watch?v=XmRLJ4XvpZk 
The shortcode is
<pre><code>[ytcode ytid="XmRLJ4XvpZk"]
[ytcode ytid="XmRLJ4XvpZk" tit="Vemma Strategie Deutsch"]
[ytcode ytid="XmRLJ4XvpZk" tit="Vemma Strategie Deutsch" x="800" y="488"]
[ytcode ytid="XmRLJ4XvpZk" x="800" y="488" ppic="2"]
[ytcode ytid="XmRLJ4XvpZk" ppic="default"]
[ytcode ytid="XmRLJ4XvpZk" fso="v"]
</code></pre>
<ul>
<li>Options:</li>
<li>
float=”left|none|right” 
if float is none, you can choose the alignment:
</li>
<li>
align=”left|center|right”
</li>
<li>
fso=”h|v|n” 
horizontal, vertical, none filmstripes
</li>
<li>
ppic=”default|1|2|3″ 
takes the previewpic from youtube. This are the four possible picture-names.
</li>
<li>
vb=”prettyphoto|fancybox|blank” 
if installed it uses prettyphoto or fancybox. Or it opens the video in a new tab (target=”_blank”)
</li>
<li>
pfeil=”FF0000″ 
the color of the arrow is now red
</li>
</ul>
<h3>Arbitrary section</h3>
*Known Issues: 
 – Publishing an Artikel/Site or update ist can cause an error-message “Warning: Cannot modify header information – headers already sent by (…)” 
 maybe this is theme specific or it depends to other plugins!
<h3>A brief Markdown Example</h3>
Unordered list:
<ul>
<li>Make opacity from the overlay-pic with the arrow on the preview-pic adjustable</li>
<li>resizing of the previewpic doesn’t work correct!</li>
</ul>
Here’s a link to <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> and one to <a href="http://daringfireball.net/projects/markdown/syntax" title="Markdown is what the parser uses to process much of the readme file" rel="nofollow ugc">Markdown’s Syntax Documentation</a>. 
Titles are optional, naturally.
Markdown uses email style notation for blockquotes and I’ve been told:
<blockquote>
Asterisks for emphasis. Double it up for strong.
</blockquote>
<pre><code><?php code(); // goes in backticks ?>
</code></pre>

ytlink

Makes a preview-pic out of the short youtube-id, uses fancybox or prettyPhoto

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.

ytlink vs Simple YouTube Responsive