I often see blogs that display the most commented post on the sidebar of their site. It is a great idea since it showcases the most talked about article and helps build a community around the discussions on your site which means more user engagement and more visits to your website.
First, install the WordPress popular posts plugin. This plugin can show the most commented post as well as the popular posts by comment counts as well. Simply install and activate the plugin.
This plugin also lets you display your most commented page or post and it allows you to showcase the most engaging content using shortcodes.