OpenOffice.org 2 is the leading open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers. It stores all your data in an international open standard format and can also read and write files from other common office software packages. It can be downloaded and used completely free of charge for any purpose.
Download link: http://openoffice.bouncer.osuosl.org/?product=OpenOffice.org&os=winwjre&lang=en-US&version=2.4.1
Screenshots: (Thx to ladidadi)
Latest version: 3.0.0
My opinion: this office pack it's as good as microsoft office and it's free
(If you think my reviews are useful you can report me as a moderator if you want, or at least a good reputation)