Ubercart Mods
Canada Post Shipping Calculator - http://www.ubercart.org/contrib/1422
Advanced Modules
http://drupalmodules.com/module/captcha
http://drupalmodules.com/module/lightbox-v2
http://drupal.org/project/accessibility
Essential Modules
http://drupal.org/project/dhtml_menu
http://drupalmodules.com/module/drupal-administration-menu
http://drupalmodules.com/module/html-purifier
http://drupalmodules.com/module/views
http://drupalmodules.com/module/content-construction-kit-cck
http://drupalmodules.com/module/pathauto
http://drupal.org/project/install_profile_api
Content Related Modules
http://drupalmodules.com/module/fckeditor-wysiwyg-html-editor
http://drupalmodules.com/module/tinymce-wysiwyg-editor
http://drupalmodules.com/module/webform
http://drupal.org/project/feedback
http://drupal.org/project/simplenews
Functionality
Five Star Rating System - http://drupalmodules.com/module/fivestar
Acidfree Image Albums - http://drupal.org/project/acidfree
Display Related Modules
http://drupalmodules.com/module/quick-tabs
http://drupal.org/project/active_template
Control Panel - http://drupal.org/node/32400
Printer Friendly Pages - http://drupal.org/project/print