xssfun,
You might want to add Quick Office HD Pro and OFfice2HD to your paid list. I've had Office2HD since I got my Ipad 1 in May 2010 and its very good and quite reasonably priced. The developer consistently adds upgrades. It is integrated with Dropbox and a number of other cloud services But not Icloud. It does not do automatic syncing however. Quick Office is pricier but syncs easily with Dropbox and other cloud services but not Icloud. I also have Docs to Go but don't like its method of syncing and integration--convoluted compared to others. I also have had Pages since the beginning but since I use Dropbox it doesn't work well for me.
Both of the above work with docs, spreadsheets, allow viewing of PDFs. There are a number of other apps that open docs and PDFs also.