Hello GtG,

I've been looking at new parts for my PC for ages now and keep hesitating on what to get. I'll of had my PC for about two years come February and it's gotten to the point where it's clearly fallen behind performance wise. I keep hesitating on my purchases because I never know if I'm getting the best bang for my buck. I'm usually not picky about prices because when I had my PC custom built (by Systemax) I just went with the name brand stuff I've heard enough about. However this time around I've seen that I could of went about getting it a lot cheaper with even more 'bang'. My current PC specs are as follows:

Manufacturer: Systemax
Processor: Intel Core 2 Duo CPU E4500 @ 2.20GHz (2 CPUs)
Memory: 2046MB RAM
Hard Drive: Two 250 GB Harddrives
Video Card: NVIDIA GeForce 8600 GT
Monitor: 19" Black LCD Monitor
Sound Card: Realtek HD Audio output
Speakers/Headphones: Realtek HD 3-Piece Speakers / Steelseries 3H Headset
Keyboard: Comfort Curve Wireless Keyboard
Mouse: Logitech Wireless Optik Mouse
Mouse Surface: Default Blue Pad
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 2
Motherboard: nVidia nForce 680i LT SLI Motherboard
Computer Case: Mid-Tower Chassis

What I'm looking to do is buy only the necessary parts it will take to run Next-Gen games at a high (comfortable) quality, or for example: Call of Duty 4 @ a constant 250FPS; install them myself into my PC in replace of the previous part, and STILL have smooth gameplay. I know what's out there as far as brand names go but I still don't know the difference between some of them (ex. AMD/Intel ATI/nVidia) I can afford to spend anywhere between $300-700 at the moment but would rather keep the price range between $300-550 IF possible.

If a few of you could clarify some of my confusion as far as the different brands go (better performance, reputation, durability, etc..) as well as help me choose hardware that fits what I want to do and my suggested price range, I'd greatly appreciate it.

Thanks!