Personally, i'm using Joomla (www.joomla.org) feel free to take a peek at my site at www.intelbank.com or www.OffroadInsider.com <- currently under construction, but a few elements are already visible and functional, including videos, forum, images.
However, since there are tons of free CMS systems available, the best resource to find out what would suit you best is www.cmsmatrix.org where you can run side by side comparisons of the CMS of your choice.
I have some sites with Joomla, for me the best CMS, Drupal and Typo3 are also between the better but are more difficult to learn. For flash are also some interesting solutions like fCMSPro or flashblocks.
only 3 CMS packages worth using
old Joomla 1.x (based on Mambo) , New Joomla 1.5 and Joomla with VirtueMart addon
I own 30+ sites using joomla
Plus teach an advanced website course using joomla
I agree with what's said above
Personally, I'm using joomla on several websites and it's great
it comes with an user manual if you want to use it :P
though it's easy and most probably you won't need to read
there are also lots of addons to it
Why?
Because it takes 3 minutes to install (including the uploading time!), its safer, faster and has nearly infinite amount of features and resources. An most important its written in REAL Perl (CGI).
I used to be a fan of joomla because it is a bit more intuitive than drupal in my opinion, but once I got past the learning curve with Drupal, I can't imagine using anything else. I love it.
Either way though, they are both great and can both do what you want.