Well, I found the answer from google, and found that this question has been asked many times, so I'm not the only one. And if there are emulators on PC, maybe there are emulators for XBox as well.
I have no experience using Xbox, but I'm at sister's house, and they have Xbox, on which my sister's little kids play volleyball with Kinect, so I thought maybe I'd try Crysis on it. Those who have both Xbox and PC, are the graphics better or worse on Xbox rather than playing it on PC with say HD 7850?
^If you're talking graphics, a 7850 will pretty much blow the Xbox 360 out of the water. It doesn't matter if the game was made for PC or was a console port; any PC with a 7850+a decent processor is much better in terms of graphical fidelity compared to the 360.
What about the newer Xbox? Not sure, but maybe its not released yet; I don't follow console news. But would it have better graphics only in comparison to 360 or would it compete with a PC with an HD 7850?
We can be sure only after we see the games for ourselves, but yeah- in all probability the games on the Xbox One will look better than with a 7850. Maybe not during the console release, but surely after an year. The GPU in the Xbone is (rumored) to be the equivalent 7790, which is slightly worse than a 7850. But remember that it's always easier to code for a console, so in a year the devs will learn to juice out more power from the Xbone.
I really don't know much about hardware either, but despite the new console having the x86 architecture, there are still a lot of differences between the hardware of theses consoles and PC- so we can't tell a lot by only comparing the GPU; only time will tell for sure. But as I said before, the Xbone wil most likely outclass the 7850 and even the 7870 within an year.