Me PS3 and Wii, I consider my desktop a 360 as it is.
Reason for PS3 and Wii, I enjoy the games more on these particular units more, and I am not required to pay a yearly for internet access off these machines (not yet anyways). Also, titles from NIS are available (Like Disgaea).
Reason I consider the desktop as my 360... Games that comes into 360, are easily available for the PC side (games that I do want to play anyways), also... I get away from my desktop, leave and return to my desktop.