The thing I like most about gaming on a PC is that I'm not forced to use the hardware that one company wants me to use. A console is basically stuck in time, technologically speaking. If my graphics start to chug on the latest games, I just upgrade the graphics card. The current one is a couple of years old, and about due for an upgrade. I consider a couple of hundred bucks a year to be a bargain for being able to stay reasonably current. The PS3 came out in 2006. The PC I was using in 2006, although in the same case, is a very different computer to the one I use today. They expect the PS3 to be the current-gen for at least another 3 or 4 years. I'll be upgrading my computer at least a couple more times by then.
Also, all my games run at 1080p. I can go to 3D anytime I want to upgrade my monitor, and I'm considering a triple screen setup after finding out about some freeware that'll do it (I already have some freeware headtracking and a homemade LED hat). The possibilities are endless, and only limited by my budget. Not being locked into Sony or Microsoft's rather ponderous development cycle is worth paying any price for. Obviously, I'm a bit of a tinkerer, but jeez, how can you be into computers and not be? Upgrading a PC, or even building from scratch, is about as complicated as plugging in a lamp - just match the plugs.
You can even plug one into a big TV and a gamepad and play on the couch if you so choose.