How to add subtitle for menu items in Nice menu in Drupal 7
Try OM Maximenu module


  "Maximize your main navigation by adding text, images, videos,
  slideshow, tabs, menu blocks, user info ..."
  
  That is now possible by using OM Maximenu which can create menus with
  all other module blocks you want as attachments, modules like views,
  slideshow, menu, user, nice menus, quicktabs, and custom blocks with
  tables, lists, images, videos, etc.


Here a great list of menu 7 Mega Menu modules for Drupal