Recommended Drupal Modules for an Ideal Base Package

I'm sure there are great arguments for starting out with nothing but core modules, and I'm sure there are even better arguments for every installation having all 32 of your favorites. This post, however, will outline a handful of modules to extend a basic Drupal 6 package into something that ought to have everything a client's website will need. The final package will  include hands-free SEO, dynamic blogging capabilities, search engine (and eye) friendly URLs, and a handful of other bonus features.

- Core Distro of Drupal 6
- Content Construction Kit - to create custom content types, with as many fields and field types as it needs.
- Custom Breadcrumbs - gives users back-tracking ability. This kind of stuff is very important for creating a solid feel to your site.
- FCKeditor - give your clients (and you) a break. This dynamic editor allows for copy-and-pasting from Word, which your client's will love, and gives the ability to upload and attach images / files to the body of any content.
- Flat Comments - comments deserve the "flat" feel that visitors are used to. This will eliminate confusion (and explanations) with your clients and users.
- Global Redirect - avoid duplicate content (with automatic 403 redirects!).
- Page Title - force page title based upon content.
- Path Auto - paired with Global Redirect and Page Title, this gives you the best combo against duplicate content and helps with navigation and SEO.
- Piwik - killer open-source analytics software, Piwik will show you visitors, stats, trends, visit time length, search engines, keywords, external websites, and more. Heavy ajax has been implemented for fast response and the ability to create pretty pie charts on the fly. While Piwik is a stand-alone PHP/MySQL app, this module gives you visitors and stats right into Drupal. <- I really recommend Google Analytics over Piwik. 
- Privatemsg - the ability to PM other users for collaborative needs
- Token - dependency (replaces strings with tokens, read the page for info. very cool module.).
- Views - if you haven't used Views, do yourself a favor: spend 2 hours watching tutorials and reading the documentation, then go create some killer views and be amazed at its abilities. Views gives you dynamically updated blocks, pages and feeds. These can be based upon parameters, users, filters, relationships, arguments, etc., for any content from your database.
- Webform - give your clients the ability to create dynamic forms that they may need - surveys, advanced contact forms, service requests, etc.
- XML SiteMap - part of the SEO. Register with Google webmaster tools and then configure XML Sitemap. In 30 minutes or less, you'll have the whole SEO setup running on auto-pilot. Your client's new content will be in the sitemap and submitted to Google as soon as it's created (or at least as soon as cron runs).

If your users need the ability to stream private downloads (downloads which require authentication and hide the true URL), install WebFM as well. I avoid this in default installs because the current integration into Drupal is a bit messy. It's a neat module though.