Things a standard XBOX 360 can do a PC cannot: nothing
pros: better graphics than the average PC at 720p, great controller for shooter, better scrolling than a PC, indented Analog Sticks prevent thumb slips.
cons:No Wifi- limited in terms of types of games (with some exceptions) no internal hard drive, have to pay for service

Things a Wii can do and a PC cannot: motion controls
pros: really really cheap, wide range of games, plays gamecube
cons: bad graphics, shoddy controls, few inspired titles, no internal hard drive.


Things a standard PS3 can do a PC cannot:
blu-ray movies and games, a bunch of tiny things not worth mentioning
pros: supports 1080p, 3-d games and video, blu ray, wifi, expandable drive, free games and videos, wide game selection, great controller for platformers, fighting games, and racers. Motion controls that aren't mandatory. Backwards compatable. Playstation home.
Cons:Terrible Terrible trigger buttons! Trigger buttons break easily! Not all games have trophies (either do it or don't sony) Impossible to use saves from old systems. No minecraft

PC:
Pros: modable games, tons of exclusives, infinate reverse compatability. Freelancer.
Cons: Gaming PCs cost tons of cash, dwarfing the other systems