The workbench module attempts to provide the sort of editorial interface that many other CMSs provide out of the box, with a single unified interface for content management. Workbench also comes with a couple of plugin modules that offer some key functionality:
Workbench access - provides a very clever mechanism for controlling editorial access to content, based on the site structure. This is far more intuitive than trying to come up with a solution based on something like content access or simple access.
Workbench moderation - this is awesome, simply awesome. Moderating content within Drupal has always been easy, simply set new nodes to go in as unpublished, add a little view showing a list of the unpublished content and maybe add a little rule to ping an email when new content has been added. However once a node has been published, any further changes to that node will just go live straight away. Enter workbench moderation, this little module does some magic with node revisions which prevents new versions of content going live straight away, and instead introduces a configurable moderation process. We love this.
OK, so it's not a brand new module - but it is a brand new version of an old favourite. The views module is what always brings a smile to peoples faces when we do our Drupal training, even the most die-hard anti-CMS I-want-to-write-everything-myself-in-raw-PHP developer grudgingly offers up some praise when we do a demonstration. The latest incarnation offers a number of improvements in the user interface, some significant performance improvements and a host of small but useful functionality improvements (for example adding OR support to filter items).
Drupal's media handling has always been something of a sore point, and can cause a little embarrassment when it comes to training users who have experience of other CMSs. The media module has changed all that, now finally Drupal has a media manager that actually looks and behaves like a 'proper' media manager. The module isn't perfect, and it's still in the release candidate stage, but we are successfully used it on a number of production sites without trouble.
Not the most exciting module but essential for almost every site. Metatags quick has the advantage of being pretty much the only useable metatags module for D7, with the new 'metatags' module still only at the alpha stage - and pending a couple of core bug fixes.
OK, so it's not a module it's a theme - but it does have it's own 'delta' helper module. Omega is a super powerful, super flexible responsive HTML5 960 grid based theme - what more could you ask for. It's not light (especially if you are used to starter themes such as basic), and it does take a bit of getting used to, but it more than makes up for this when you start configuring that small screen version of your site!