A well built gaming PC is superior to any console.
That's right. Your Xbox or PS3 isn't worth shit compared to a gaming computer. Here's why. Gaming computers have interchangeable parts. You can buy a better graphics card than an Xbox, and put it into your computer. Hell, depending on your motherboard you can buy MORE than one. Same thing with processors. I read an article on how the next generation of Xbox is going to have a quad-core processor "better than any gaming computer." I laughed as I read that, then proceeded to shop for already existing and on the market six-core processors on Newegg. Besides, computers never get the "red ring of death". If a computer has a problem, it's a lot easier to fix it. If an Xbox gets red-ringed, you have to pay more money and take it back to the shop. They refuse to let you do your own repairs in order to get more money out of you. When you built your own computer, you know what everything looks like, what everything is supposed to look like, and more or less how to fix it. If any part of the computer gets completely fried, no problem, just replace the part yourself. Optical drive broken? 20 bucks and 10 minutes later, you're good to go.
In terms of software, PC wins again. Xboxes and PS3s can only play the games that you have on disc or are on the distribution network. Older games or retro games are completely lost on the console, you can't play them unless you kept your N64 or PS1. With your PC, you can download Project 64 or ePSXe, configure it, torrent your favorite games, and play away. Most games that are available on Xbox and PS3 have been ported to PC anyway. There's only a few exceptions to this, like some sports games, but that's only because the audience that plays those games don't usually use PCs because sports games are for casual gamers. If you're used to a controller instead of the keyboard and mouse (which is better for FPS games, especially with a R.A.T. 7 mouse), you can actually buy an adapter for a couple bucks and plug in your controller. A lot of games are already optimized for Xbox or Dualshock 3 controllers. If they aren't, there's programs like Joy2Key available. Speaking of programs, the game distribution platforms for PC are honestly superior to the PlayStation Network or whatever the hell the Xbox thing is. Steam has thousands upon thousands of games, ridiculous sales that make them all dirt-cheap, and they have an excellent layout that lets you mod games easily (another thing PCs can do a lot easier), chat with friends while playing or fix glitches without even exiting out of the game.
The things you can do on a PC that you can't on an Xbox or PS3 is really the final nail in the coffin. A gaming PC isn't only for gaming, it's for browsing, word processing, making videos, chatting with friends, picture editing, flash animations, you can do so much on a PC that you can't on a console. The only thing that really keeps people from getting a decent PC is the price. But if you know what you're doing, you can build a really decent computer for under 300 dollars, and add onto it as time goes on and parts go obsolete. The only reason people get consoles is because they either don't know how to (or that you even can) build a computer, or they're morons who think consoles are superior.
To prove that last point, I recently got into a (short) argument with an Xbox fanboy. He wouldn't bring up any valid points for his side of the argument, and after a few minutes I found out why. He didn't know anything about consoles, or how they worked. He thought graphics were dependent on what kind of TV you had hooked up to it. He didn't understand the concept of a "graphics card", and started accusing me of making it up. This is the reason people prefer consoles over PCs; they're plain old stupid.