Ryujinx is an open-source Nintendo Switch emulator created by gdkchan and written in C#.
This emulator aims at providing excellent accuracy and performance, a user-friendly interface, and consistent builds.
As of September 2021, Ryujinx has been tested on nearly 3,400 titles: ~3,000 boot past menus and into gameplay, with approximately 2,400 of those being considered playable. See the compatibility list here.