First off, lets talk need over want. If I'm not mistaken, Half Life 2 has sold over a million copies already (I'd bet my life on it). Now, do you honestly think that everyone who bought Half Life 2 is running a 4.0 overclocked watercooled PC? Nope. They're running what they have, and that works. In fact, my 32 mb Video Card in my laptop (And remember, this being a laptop, the video card can't get enough juice to even display nicely) can run Half Life 2 (Granted its a laptop, so it overheats). You don't need to shell out $4000 to play FarCry or Doom 3, thats just what they tell you.
Now for those of you in my situation. Us who literally played through Half Life 2 with 5 fps. Those of us who play CS:S and always get killed because it takes us 5 seconds to do a 180 flick. Those of us who just damn want a powerful PC, and will kill to get it.
Don't forget that any PC that has been made in the last 4 years is very upgradeable. Thinking about it, any computer could be upgraded faster as long as you handle it right. The biggest problem is your Motherboard- if it doesnt support your upgrades, you may as well get a new computer. An old Motherboard teamed with new parts will usually slow down the parts, and that's a lot of money down the tubes. All fear the mighty Front Side Bus.
Okay, so if you've read all that and are still hellbent on building a new PC, or if you just wanna see me crash and fail at my first time building a PC, these articles will be out as soon as I do something to build this new PC. In a few days, I'll write another article detailing my PC build, and why I chose it. Who knows if I'll even stick with that, being as I change my plan so much. But you'll get all the info from me so you can make your decisions wisely.