Both have some pros and cons, its up to you which one is best suitable to you. Drupal can work with MySQL and Postgres while Joomla is known to support only MySQL and also It can work with Apache or IIS while Joomla is known to support only Apache. Joomla support SSL logins and SSL pages. Drupal not known to support it.
Drupal:
* Rock solid & high quality platform
* Real multi-site-feature
* Drupal has free add on for Workflow management. Joomla not known to have one.
* Drupal has inbuilt Translation manager. Joomla has a Free ad on for the same
* Drupal has more granular priviledge managment
Joomla:
* If you are not techy its good to start
* Easy install & setup with your mouse
* Easy learning curve
* Cannot integrate other scripts etc. to your site
* Generally you cannot create high-end sites, without investing huge amount
* No
SEO out of the box, URLs are not search engine friendly.