Consoles are convenient because you don't have to constantly upgrade your hardware, but this comparison screenshot says it all when it comes to the power PC graphics have over consoles.
The PC screenshot was taken with the GTA IV iCEhancer and a few other mods enabled.
Click the image for a larger size or click here to view the full 2000x2300 resolution image to see all the details.
Image submitted by WL.
Video example of the PC version: