Personally the best Snes emulators for me are:
1 - Snes9x (It has an ok GUI with plenty of options and it's very compatible)
2 - Mesen-S (It has a pretty good GUI with plenty of options, this one is probably the least compatible in this list but I may be wrong, it's still top tier)
3 - Bsnes (It has an ok GUI and the best compatibility, it's not my default emulator though because it's missing an important feature for me)
The reason I will go with Snes9x or Mesen-S over Bsnes is because of the Save State/Load State GUI which is an excellent feature on those 2 emulators, Bsnes doesn't have it so it's an instant turn off for me. To be fair Bsnes does have something a bit similar with the Save State/Load State GUI but the implementation is godawful in it and is something I will never use in Bsnes but in Snes9x and Mesen-S I will use it all the time.