What are the best emulators for gaming?

[Grant]

I'm aware of a few emulators like; Xenia (Xbox 360), Snes9X (SNES), higan (multiple consoles like NES, Genesis, and more), pcsx2 (PS2 and maybe PS1), and I'm sure of a few others, but I am forgetting their names. What would you say are the best emulators for other consoles not mentioned? Or ones you would recommend?

 

[Kane]

I have used Bluestacks for Android and it is the only emulator I have used. I do not know about other emulators. I did not like emulating Android games on PC, therefore, I have stopped using Bluestack.

 

[The Raven]

I am using Nox emulator for Android games on PC.