1. Devel

helper functions for Drupal developers and inquisitive admins. This module can print a summary of all database queries for each page request at the bottom of each page.

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2. Drupal for Firebug

This module is a helper module for a customized Firefox plugin that displays Drupal debugging and SQL query information to the Firebug window.

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3. Admin:hover

This module adds administrative links to nodes and blocks for users with proper permissions to easily edit content. These links conveniently appear when the user mouses over a node or block, and then disappear on mouse out.

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4. Control Panel

This module adds a new graphical control panel page. It allows the user to specify the menu path to use as the source for the Control Panel.

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5. Drupal Administration Menu

Drupal Administration Menu provides a theme-independent administration interface (aka. navigation, back-end) for Drupal. It’s a helper for novice Drupal users coming from other CMS, a real time-saver for Drupal site administrators, and definitely a must for Drupal developers and site builders

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6. Web File Manager

The WebFM module presents a paradigm shift in file management for Drupal. This file manager is based on a heirarchical directory structure unlike the traditional flat filesystem used to date.

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7. Poormanscron

A module which runs the Drupal cron operations without needing the cron application.

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8. Backup and Migrate

Backup and Migrate simplifies the task of backing up and restoring your Drupal database or migrating data from one Drupal site to another. It supports gzip, bzip and zip compression as well as automatic scheduled backups.

via 8 Amazing Drupal Utility Modules | Dezinerfolio.