Consoles versus PC is a matter of preference. I find that many console gamers have simply never experienced true PC gaming (mouse and keyboard, online multiplayer, etc.) and therefore are not able to properly compare consoles to PCs. Most PC players have played and/or owned consoles, so we tend to be a bit more open minded about which platforms we prefer to play on. Bottom line, I find that PC games are much more competitive and addicting. They also often times aim for hard core gamers, so you aren't stuck with a "made for mainstream" set of dumbed down games.
As for cost, I built my last PC, and it rocks. I did a lot of research and found excellent deals on Black Friday of last year. Some of the deals were simply amazing. Bottom line, I built a great gaming PC for below $800 (or was it below $900? can't remember) and that includes a Samsung 19 inch wide screen LCD. Also, the software on my computer alone is worth more than a console. Right now, I can purchase a video card that is more powerful (theoretically) than all previous consoles combined for around $200 or less. Trust me, consoles look nice, but moderate to high-end PCs will run circles around consoles, and consoles will then later adopt the PC technology for the next generation systems. So, in effect, you are playing on a medium performance PC when you currently by a PS3 or an Xbox 360. No shame in that, but at least know what you are buying. Yes, I know they optimize better for consoles, but the extra raw power of PCs can more than make up for that lack of standardization.
I am finishing up a masters degree, so I frequently use my PC for homework, something I could never do with a console. Of course, I also use it for its basic functionality that is quite akward on consoles (really, whoever sends emails from a console? I'd like to see someone who really does, not that you couldn't). Fry's on Wednesday was selling a 2.83 ghz Core 2 Quad with 12 MB L2 cache and a motherboard (a crappy mobo, but at least it came with one) for $230. You can find amazing PC deals, you just have to be willing to build your own system, which is really not that hard. You also get to choose the components of your system, so you don't get stuck with anything that is low quality. With consoles, you just have to accept the product they give, knowing that some of the components are low cost rather than performance parts
As far as games are concerned, I am able to use networks such as Steam to download games that other people I know have bought. We share accounts so that we can play each others games. Try that on a console, I dare you (show my one console user that paid $22.50 for a legit, non-asian copy of Far Cry 2 brand new). I also get games extremely cheap off of eBay (I know, you can do that for consoles, too). If you want the latest and greatest PC game and don't want to wait, you will pay less than you will for the same, often lower graphics capable version on a console (console makers demand a royalty fee that pushes the expense above a PC game). I just got a brand new copy of Fallout 3 for $26.50 after live cash back. Find me a console user that is paying $26.50 for brand new, non-pirated Fallout 3. Try $50 to $60, most likely, for the average console user.
Those extra charges for games really add up over time. Also, to enjoy a console, I feel like you really have to have a full set of controllers. That'll set you back how much? $30 to $40 per extra controller? So, to get for, you pay for three more at a cost of $90 to $120? How about new batteries for those wireless controllers? How about the Xbox live account (for PS3, you don't pay, but you also don't get as good of a service, so don't even compare)?
Finally, to see a console's nice graphics, you have to buy an HD TV. So, how much of a TV are you going to buy for that console? A 30 inch for $400+? A 40 inch for $700+? 50 inch? Can you turn down the graphics on a next gen game and stick it in a console to extend it's life? No, you can't, you just can't play the game.
/rant