Those which I have not used personally or which do not run on Windows are omitted.
AbiWord: word processor only.
Lotus SmartSuite: descent productivity tools. I have a copy of the 97 version. I used it but wasn't impressed enough to drop other stuff and switch to it.
OpenOffice: Full featured. I have it on my Linux partition. Operation is somewhat similar to MS Office but has some other very nice features (so it is not just a clone).
StarOffice: Think OpenOffice with some proprietary addons (LH spell checker, clipart, etc.)
WordPerfect Office 2000: Wordperfect is good stuff. Stable and less bloated than MS. Wordprocessor offers composition power and flexability via embedded codes. Spreadsheet commands are significantly different from excel.
Havn't used the 2000 version but it should be better than the earlier version that I use.
Also, you should consider
LyX as a document preparation tool. Takes some setup work on Windows, though.
As propritary software goes, I like WP. OpenOffice and StarOffice are nice.
[ August 27, 2003: Message edited by: M. O'Brien ]