I have tested the top 3-4 most popular facebook like modules for my new joomla! 3 site and i can confess that this is the most simple, effective and, not to mention, free. Yet it has many options but without being complicated. It is also recommended for multilingual sites, since you can setup multiple instances of the same module with different language display options and configure each instance to appear in the selected language. This is very handy for my greek-russian-english site. Keep up the good work!