(re: Patch Archives) Large resource of patches:
Link: http://www.patches-scrolls.de/(http://www.patches-scrolls.de/)
Sierra specific patches (unofficial):
Link: http://geocities.com/belzorash/(http://geocities.com/belzorash/)
The latter site contains SCI script fixes specifically to get around the timer issues a lot of Sierra games have when running on modern systems.