Hi,
as many others, I use FinalWriter for simple tasks like writing letters or creating the texts for my eBay auctions (it has an HTML export). I have used FinalCopy the years before -- also good enough for simple letters.
AmigaWriter has some nice features (the only word processor that allows to chose between different printers if used with OS 3.5+) but in my oppinion it is not so easy to use as FinalXXXXX.
For complex documents as my diploma work I use(d) PasTex. This LaTex-implementation can be found in Aminet and produces professional results (if you don't need WYSIWYG).
Noster