A lot of people get conned into buying computer parts that are, honestly, pathetic. If you walk into certain retail outlets in Australia, and I'm sure this happens in other countries, the salesman will probably try and sell you a TNT2 M64, which they claim gives super fast frame rates, and comes with a massive 32MB of RAM! Obviously, these salespeople don't know that they are talking about, but a lot of people do believe them, and will be very disappointed when they throw Quake 3 at the TNT2.
By reading this guide you can get an understanding of what is good in the crowded marketplace, and can make an informed decision. The products here are not always the number one performers, or the most feature packed on the market, but they are a product that excels in both of those fields. If you don't agree with what I list (which I imagine will happen with the P4 2.4Ghz) that's fine with me, but remember these products are certainly among the best on the market, so you wont be disappointed if you buy them.
Just remember; always opt for quality over a cheap price. They will last longer, perform better, and you will have a lot more fun with them.
We'll be keeping this Buyers Guide updated every two weeks, keep your eye out for the next edition!