A lot of people on here have good points. You can build a pretty good gaming computer with 1500, or even 1000. Since you are aiming torward gaming, your main concern will be a great video card. I generally wouldn't suggest using an onboard video card for gaming. The guy that siad to pay attention to the chipset on the motherboard was very correct. Some motherboards with one chipset won't work well at all with some video card chipsets. You usually want to try to match them up.

For example NFORCE and NVIDIA do not agree with ATI video cards well at all...

You are most likely best off getting a motherboard that has an NVIDIA chipset AND a video card with NVIDIA chipset. They will work flawlessly. Don't fall for the extremely expensive video cards as there are plenty out there that will give the same if not better performance for half the cost. I got the radeon 9600 which is an ati card but it matches the chipset on my motherboard. It is a 256 meg card, cost less than 100$ and plays doom3 flawlessly.

One other thing with the ram you choose, make sure it will work well with the motherboard. Most new motherboards have new things like dual channel. To use that you would have to get ram that would be compatible with it or that feature is pointless.

DFI makes great boards for instance the DFI Lanparty NForce 4 sli-dr. This is a great board for gaming and is only around $200. ASUS also makes great boards but they can be slightly expensive.

Going with a AMD processor is usually a better idea since you get more bang for your buck. A 2.0ghz amd chip vs a 2.0ghz intel chip, the amd will be a decent ammount faster.

The word you were looking for with the case is Barebones. A barebones system will usually come with a case, motherboard, memory and a video card and sometimes a hard drive. You can buy a case either with or without a power supply. Usually you can get a better deal just getting them together. You can get some with lights and stuff to if you want. For the setup you are trying to run you would most likely want a 550wat power supply or something around there. Make sure the power supply is compatible with the type of motherboard/processor you are running. I.E. Intel or AMD.

So heres your list of what you need to concern your self with now:

Case / Power Supply
Motherboard
Processor - don't forget to get heat transfer paste if it doesn't come on the bottom of the heat sync
and don't forget to make sure you get a heat syinc either with or seperate from the processor
Memory
Video Card
Sound Card - usually some kind of sound blaster is good but if the mobo comes with sound it should work just fine
Cd Drive / DVD Drive
floppy drive - they are still usefull...
Lan card - your motherboard will most likely come with one so you probly won't have to worry about this...


If you have any other questions please feel free to ask... I've been building computers for over 10 years and now i work at CNN on everything from hardware, to software, to networking etc...