Yabause is an open-source Sega Saturn emulator.
There have been several versions of Yabause released, including a currently work-in-progress core for RetroArch. There is also a Wii version, linked above; note that this is an unofficial release and support from the Yabause developers cannot be provided for it.
Developer devmiyax has forked Yabause to improve it.
Yabause has a very decent rate of compatibility, around 70% of the games run well or perfectly.
Yabause has many advantages over SSF. If you use the OpenGL video driver, games can be rendered in higher resolutions, unlike SSF which can only render in the game's native resolution. It is multi-platform and open-source, unlike SSF, which is closed-source and Windows-exclusive. SSF only lets you run games via mounted/burned disks, while Yabause lets you open ISO files as well as run burnt/mounted disks. The UI, despite not being perfect, is also better than SSF. What matters is compatibility, and SSF is far ahead in that regard. Yabause is recommended for its features for the games it is compatible with. Use SSF for everything else.