Official website for SSF run by the author - in Japanese.
Giri Giri Homepage
A Sega Saturn / Sega ST V emulator written by a clearly talented French programmer. It looks like this is catching up or even overtaken Giri Giri in progress which is amazing as its not been in production as long.
Its worth noting that there ARE other emulators but they havent been updated in a long while so they arnt listed here as they are probably dead.
Home of the first SSF compatibility list. Lists all the Saturn emulators in production amogst other useful Saturn stuff.