Is there a working Xbox emulator out there?

[LDClaudius]

I think the closest emulation you can get is CXBX-Reloaded. You can check it out here: https://github.com/Cxbx-Reloaded/Cxbx-Reloaded

Keep in mind that not all original Xbox game currently work at the time of this writing. I'm pretty sure the emulation dev are currently working on getting the Xbox game to support the emulation.