The cookie law is active since June 2015, and the fines are crazy. So if you still don't have it on your website you need to hurry up.
jQuery UE Cookie law popup is an easy-to-install jQuery plugin to create EU Cookie Law popups Supports multiple layouts out of the box. Works well with Bootstrap 3 and is easy to customize markup and CSS.
CookieCuttr is implements a simple solution to the EU cookie law. Is easy to use and customizable. Requires jQuery and jQueryCookie plugins.
The homepage has an useful "customization process" that will help you to add it faster.
Cookie consent is the most popular solution to the EU Cookie Law, is free and open source. The website has a menu to help you to configure the plugin, this can be located in different locations of the screen. It's lightweight, just 3.5k when minified, and you don't need JQuery or anything else. It can be easily customized, you can choose from one of the built-in themes or build your own with CSS.
If you know of another awesome Cookie Consent plugin, please share it with us in the comment box !