I just installed the Drupal Administration Menu contributed module, and I really like it. When you are logged in and have administrative privileges, it provides a small menu bar with drop-down menus and submenus at the top of every page in your site. It provides quick access to every admin function I’ve needed, and really streamlines the process of making changes to the site.
Here’s a screen shot of what it looks like:
In that respect, I rank it up there with the Taxonomy Manager module, which also provides a major productivity boost.
Update: Apparently I’m not alone; Administration Menu is among the modules included with the Acquia Drupal distribution. I think that lends quite a bit of credibility to this module … if my own recommendation didn’t provide a tipping point for you.