I can’t recall how many BIM document PDFs I have downloaded over the years.  There are web indexes of the indexes of the lists of standards you can access…

But here is a simple list by Ben Malone:
https://docs.google.com/folder/d/0BwLLFYLrgVI6WldMeFlDQ1hSVE0/edit?pli=1

It looks like it might be a work in progress – there are still plenty more that could be added (and probably will be, when Ben finds the time 🙂

Note – if you click the “Open in Drive” button, you can then check all the boxes and click Download to get them all at once…

Heads-up from Dave Light:
Revit: BIM Docs!