I've collected a few freeware sets over the years here is a list of my favourites. These are samples and instrument patches that are legally free as they have been generously made freeware by their creators.
I'm not posting links, because some of the sites have rules about direct links to the samples since they make their money from the ads on the site's main page....
Here are the ones I think are the best:
1) The Akai Splendid Piano, which is hard to find in the original format (the one I have), but it is available as a free soundfont...just google splendid pinao soundfont. It was originally an akai instrument that akai provided for download for free on their site but the original link is dead. I have no knowledge of the copyright legality of the conversion to soundfont from the original samples if you are concerned, contact the Splendid Piano soundfont's creators, not me. I would provide an upload to the original Akai samples except that I do not know if I would require permission from Akai to do so.
2) The upright bass samples at echochamber (you must google the following: echochamber.ch and then click "translate this page" which is a blue colored link on the google list...then look for exs instruments link. It is a set of zip files called doublebass1.zip etc. this instruments can be converted to Kontakt. Note that there is one sample missing because of a corrupt zip so if you use this as a exs/kontakt instruments, you'll need edit the patch to stretch one of the other samples. But the set sounds very good.
3) The Maestro Concert Grand by Mats Helgesson
4) The university of Iowa electronic music studios...various anechoic samples but no patches, so mostly only good for single note samples unless you want to spend a lot of time programing. Here is a thread where one fine gentleman did some of that work for us: http://www.northernsounds.com/forum/...5&postcount=35
The anaechoic samples would also be usefu;l if you download a few notes to compare with pro library samples for educational purposes such as analysing reverb qualities or comparing convolution impulses to find one that most closely matches the original.
Others have added many more great links in this post which has grown over time. I thank everyone for there interest and effort.