Wysiwyg Feb 23rd, 2013 (updated Oct 11th, 2017) The WYSIWYG module is my favorite for rich text editing in Drupal 6 and Drupal 7. (In Drupal 8, WYSIWYG is in core.) Here's how I set it up. Read more about Wysiwyg
Configuration Update Manager Jun 23rd, 2016 (updated Jul 3rd, 2016) This module is essential for configuration management in Drupal 8 Read more about Configuration Update Manager
View Mode Selector Jun 23rd, 2016 This module adds a view mode selector field to any entity Read more about View Mode Selector
Allowed Formats Jun 21st, 2016 This Drupal 8 module allows to restrict text formats on fields. Read more about Allowed Formats
Field API Pane Editor (FAPE) Sep 12th, 2014 (updated Jun 7th, 2016) Allows for quick editing of field type panel panes. Read more about Field API Pane Editor (FAPE)
Metatag May 31st, 2016 From the Drupal module page, "The Metatag module allows you to automatically provide structured metadata, aka "meta tags", about a website." Read more about Metatag
Focal Point Nov 25th, 2015 (updated May 31st, 2016) Sponsored by NBCUniversal, the focal point module seems to have been inspired by the image field focus module Read more about Focal Point
Region View Modes Nov 5th, 2014 (updated May 31st, 2016) "A surprisingly simple, flexible layout solution made possible by placing fields in regions. Region View Modes is just a bit of glue to join Drupal's theme regions and View Modes." Read more about Region View Modes
Taxonomy field formatter May 31st, 2016 This Drupal module provides a new field formatter for term reference fields which outputs them as rendered entities. Read more about Taxonomy field formatter
Taxonomy Autotagger May 31st, 2016 This Drupal module will suggest terms based on the content in other fields. Read more about Taxonomy Autotagger