Must have modules for Drupal 6

These most common modules have proven so common, that they span across sites of different profiles:

  1. Admin Menu - an alternative to devseed Admin module
  2. Advanced Forum
  3. Author Pane - required for Advanced Forum
  4. Backup and Migrate - back up the database in a smart way
  5. Better Formats - a more controllable input formats
  6. Captcha
  7. Colorbox - a better Lightox alternative
  8. Content Construction Kit (CCK) - extend content types with more fields
  9. Chaos Tools - an API needed for many other modules like Panels, Spaces, etc.
  10. Date - Date field extension for CCK
  11. Devel - a must have when developing modules and themes
  12. Dialog - required for Skinr UI
  13. Display Suite - required for some of the UI modules
  14. Embedded Media Field - a media extension for CCK
  15. External Links - place indicative icons after external links
  16. FileField - attach a file or image functionality for CCK
  17. FileField Sources - allows filefield items to be imported from elsewhere
  18. Google Analytics
  19. IE CSS Optimizer - fix the "IE 31 css files bug" for module and theme development
  20. ImageAPI - work with gd2 or ImageMagick image toolkit
  21. Internationalization (i18n) - make web site translatable
  22. jQuery UI - dynamic interfaces required for many modules
  23. jQuery Update - jQuery update for UI interfaces
  24. ImageCache - auto size and crop images for display
  25. ImageCache Actions - Additional functionality for ImageCache
  26. ImageField - extends FileField to support images
  27. IMCE - upload images and add to posts with WYSIWYG
  28. IMCE - WYSIWYG Bridge - needed for WYSIWYG to support IMCE
  29. Menu block - display a part of menu in a block
  30. Nodewords - edit meta tags for SEO
  31. Page Title - edit page title for SEO
  32. Link - add a link field to your content type with CCK
  33. Login Toboggan - slide-open login block
  34. Login Destination - select where users get redirected after login
  35. Panels - powerful layout and presentation suite
  36. Panels Tabs - display Panels panes in tabs
  37. Pathauto - auto-assign healthy path aliases to new content
  38. Poormanscron - run cron periodically without a crontab
  39. Print and PDF - display print and pdf links below your content
  40. Rules - an API for creating conditional behavior
  41. Service Links - display links to almost every social sharing system around
  42. Share - also required for Service Links
  43. Simpletest - Required for multiple test submods to work
  44. Skinr - theming and layout layer for blocks and content
  45. String Overrides - search override any string of Drupal interface
  46. Tabs - required for panel tabs
  47. Token - a pattern replacement API required for a host of modules
  48. Transliteration - required for work with non-ascii languages
  49. Vertical Tabs - an admin interface enhancement
  50. Views - generate dynamic content layout in a mighty powerful and flexible way
  51. Views Customfield - add a PHP code as a field in views (very powerful)
  52. Webform - create complex and secure forms with an UI
  53. WYSIWYG - API supporting a dozen WYSIWYG editors (we prefer ckeditor)
  54. XMLSitemap - xml sitemap for better SEO