Content Management Systems

Hi all,

I have been doing research on different content management systems available for enterprise purpose.

I have so far come across

Media wiki
confluence
basecamp
interwoven
plumtree
documentum
Drupal etc..

Can any of suggest me which is the best one to use???

My requirement is to setup a portal in the intranet for uploading n downloading files for a particular dept. Also to store the files (all formats) in a organised format.

Any suggestions?????

regards,

rock