Bundle Copy is in Drupal 8 Core CMI. It is a replacement for the Content copy module which lives in the CCK project for Drupal 6.

"Ctools Plugin Stub is a Drush plugin that can help you generate code stub files for ctools plugins."

Pretty sweet module. Easily build form based pages. It can have system variables for fields if the Variable module is installed. The forms are exportable. Uses the Form Builder module.

This module is a great way to easily create a form and generate the PHP form structure. Used in the Configuration Builder module.

This module makes it so you don't have to rsync the whole remote files directory on a dev machine.

Really rad developer module. Use this in addition to Devel to become super awesome. One thing I like about it is the ability to clear any cache you want; you can clear the cache from just one view, for example.

Developing with Apache Solr? Then you pretty much gotta have this installed. It will show you the entire Drupal Solr entity in a subtab next to the normal devel subtabs.

The only thing I've used Schema for is for easily seeing the differences between what's in the db and what Drupal expects to be there. Very handy for cleaning up a dirty db :) This module can also be used to do all sorts of other db related stuff and has an API used by other modules.

Easily create a scaffolding for a module. Gives a nice UI with a full list of hooks to be included, all organized into collapsable sections. Try it out. It might save you some time.

"It allows a user with the right permissions to switch users."