After delivering over 100 DotNetNuke sites we have used dozens of 3rd party modules and have custom programmed even more.  I was trying to assess what 5  3rd party modules would be the top on my list for delivering a solid website with DNN. In no particular order:

Snapsis CSS Menus – The DotNetNuke core menus have always been a sore spot for me because they have been so dependent on Javascript and the generated mark up was so pathetic with the Solpart menus.  Snapsis CSS menus provide a way to create excellent menus of virtually any complexity (drop downs, tabs, nested menus, etc.) with ease.  They are very search engine friendly, highly accessible and work across all browsers.

Ifinity URL rewriter – DotNetNuke just recently received SEO friendly URLs and you actually have to turn them on by modifying the Web.config. Unfortunately they are still in the format /Products/SearchEngineMarketing.aspx but I would prefer them to be /Search-Engine-Marketing.aspx or perhaps even / Search-Engine-Marketing/  or maybe I want to have the option to do both, or have it /SEM.aspx as well.  This module will allow you to do all of these. 

Inventua Shadow Module – Want the same content on multiple pages of your website?  By default there are only two ways of doing this in DotNetNuke.  Option 1 is to add the module to multiple pages and add/update the content in both spots.  The other choice is to use ‘display module on all pages’ and then remove it from the pages you don’t want it on.  OR, install Shadow Module and add this to a page.  Then select the page and module you would like to ‘shadow’ and it will duplicate its behavior on another page of your site. 

Form Master – Making contact forms traditionally can be a bit of work.  You have to add all of the fields to a page, then write the code to validate, and build the email to send to whomever it is that will receive it.  But with Formmaster you can quickly build rather complex forms, have them get emailed to different people, saved to a database, supports excel export, you can even have it call a webservice and pass it the data.  Recently they released a feature to support creating user accounts in the form as well.  Very helpful module.

Ventrian Articles Module – I haven’t used the Blog feature in DotNetNuke in over a year, it has always been sub-par in my book.  But with the Ventrian Articles module you can easily create a blog, or organize a large amount of articles.  Separate them into categories, it supports RSS syndication, comments, ratings, and it has it’s own type of skinning and token engine which make it easy to customize the look of your articles.