What a kick-ass thread. Unfortunately, nobody in this thread is winning. Yes, PC's versus consoles is great argument, but the fact is that the pros balance out the cons for both.
My thoughts:
Cost: Juding solely on costs, the XBOX is a clear winner. $400 nets you a ton of great hardware, top-of-the-line graphics (for now), 512MB of RAM, a $50 (retail) wireless controller, a mic headset, and decent to high quality component hookups with optical out (hell, a remote too if you want to count it). Getting the same configuration for a PC would be decidedly more due to having to purchase the individual parts, plus input devices, plus OS. Also, you'll need a monitor for a PC, compared to a television for the XBOX, which most everyone in the world already has.
Uses: Judging solely on use, the PC wins hands-down. This is a no-brainer, as a console is good for one thing and one thing only, games. But, that's what it was designed for.
Monitor: This is a tie. Everyone should have a TV already, so this is a plus for consoles. But, regular TVs only display in 480i, which isn't optimal for gaming nowadays. Technically, a better monitor can be purchased, which should be capable of supporting atleast 1024x768, and is cheaper than a comparable TV that will display those resolutions. So, plus and minuses for both. XBOX360; you should already have a TV, but HD has a high entry price point at the moment, but atleast most HD sets are rather large. PC; you will most likely not have a monitor already, so that adds even more to the cost of building a new rig, but atleast even the cheapest of monitors display decently high resolutions, but the price is high for even a 20" LCD. I purchased my 52" for the same price that the 24" 2405fpw from Dell retails for.
Games: Consoles are good for platformers, sports, and adventure, PC's are good for FPS, MMORPG's, and strategy games. Selection of games heavily favor consoles, and have been for a few years now. There are more blockbuster games on consoles (coming out quicker also) than there are on the PC.
Multiplayer: This is a tie also. At first, I thought PC win this easily because Live isn't free to get the good stuff, but Live has so many advantages once you pay for it. PC's are easily accessible on multiplayer with basically any game that's released now, but the advantages to having a Live gold account are plentiful; one username across ALL games, instantly accessible friends list in ALL games, ALL games support voice (the key here is that the voice works 10x better than any PC game with the built-in voice, although this can be countered with setups of Teamspeak or Ventrilo). However, when it comes to same-system multiplayer, consoles are the absolute ONLY way to go. You can't crowd 3 other friends around your PC monitor, mainly because monitors are typically smaller than the common TV (19" compared to 27"), plus your PC monitor wouldn't necessarily be flanked by a couch and a couple of recliners.
Am I forgetting anything? Overall, which one you prefer depends on your needs/wants. This is heavily evident by what you guys choose to argue. You may now continue.