In the my experience of Drupal I've found a set of contributed modules that I keep coming back to. The features that they provide are, for the most part, useful on any site. Those modules include the following. Menus

• Menu Trails - Maintains a breadcrumb based on your menu hierarchy
• DHTML Menus - Quick navigation via js menu


SEO

• Path Auto - Automated and manual URL aliasing
• Global Redirect - If you use URL aliases, this module makes sure that you don't take SEO hits for duplicate content.
• Page Title - Gives you more control over the Page Title

Content

• Views - Graphically build SQL queries and markup to retrieve your content and render it.
• CCK - Allows you to create your own content types
• Contemplate - Gives you total control over the template used to render the content types that you create using CCK.

Enjoy!