PCs also have access to the Steam service, which is completely free of charge to use unlike Xbox Live Gold and PlayStation Plus - Steam also has very large sales twice a year (Steam Summer Sale and Steam Holiday Sale).
Some would argue that gaming is easier on console because of the controller, but a controller can also be connected to the PC and with new services like Steam Big Picture you can sit back on your couch and play games like you would on a console. I find a mouse and keyboard is best for MMO, MOBA, strategy and FPS titles, while a controller is best for third person, side-scroller and racing games.
There is also exciting new technology like the Oculus Rift and Virtuix Omni coming to PC, this technology has the potential to completely change the way people play games.
Finally, in many games, mods can be downloaded to bring a whole new look and feel to a game (for example, Skyrim, GTA IV, etc.) which is just not possible on consoles.