JUX Mega Menu is the most completed and easy to use Joomla mega menu module which allows you to display a ton of content in menu item including text, images, module and articles. Works beautifully with Joomla 3.x and Joomla 4.x.
Documentation: http://docs.joomlaux.com/extensions/jux_megamenu/
Demo: https://joomlaux.com/jux-extensions/mega-menu/jux-mega-menu.html