Obviously, you can't go past building your own. Have a look at the following explainations and suggestions. Quoted from Marc Saltzman by Microsoft corp.
"Processor. A PC's processor is the brains of the machine. The rule of thumb is the higher the number, the better. Today, an Intel Pentium 4 chip running at 3.0 gigahertz (GHz) is a great start. You may see cheaper PCs with an Intel "Celeron" chip, but it doesn't process data fast enough to support high-end games. On the other hand, more expensive Pentium processors include Intel's "Extreme Edition" with industry jargon such as "hyper-threading" technology, but this will add more to the budget.
Alternatively, AMD's Athlon 64 processor is also a good choice. In fact, AMD's 64-bit platform extends the current x86 instruction set architecture and is often preferred by gamers for its fast performance and reliability; the Athlon 64 processor in particular is designed for applications that require multi-processor scalability and fast 3-D processing. Games certainly fit that bill. And AMD-based PCs may be slightly less expensive than Intel-based ones.
Memory. Like the processor, memory (or RAM) affects the speed and performance of your computer, and also makes it possible to run more than one program at once. Because the price of memory has dropped considerably over the years, chances are any new PC you purchase—even value-priced ones—will ship with 512 megabytes (MB) of RAM. If you look at the bottom of the box of new computer games, the minimum amount of RAM required is usually 128 MB (Splinter Cell: Pandora Tomorrow, The Suffering) or 256 MB (Thief: Deadly Shadows, Far Cry). So while 512 MB should be enough, 1 gigabyte (GB) is preferred. Also be sure you're buying a PC with DDR SD-RAM running at 333 megahertz (Mhz)—that is, higher-speed "Double Data Rate" memory that should cost about the same as regular system RAM.
Video card. One of the most important considerations when buying a new PC is its video card and the amount of video RAM (VRAM) on the card. The card will determine how fast and smooth those 3-D graphics in games render. It's easy to upgrade these over time, but you'll want to find a PC with a decent card already installed. Some recommendations include the Nvidia GeForce FX 5900 (and a few more from Nvidia), with 128 MB to 256 MB of onboard memory or the ATI Radeon 9600XT (and a few others from ATI) with 128 MB to 256 MB of RAM. Note This is considerably more than the 32 MB of VRAM required for many of today's PC games, such as True Crime: Streets of L.A. or the 64 MB of VRAM recommended for Battlefield: Vietnam.
Hard disk. Hard disk space has also come down in price over the past few years. The more you have, the more games, programs, and files you can store on your computer. Be sure to purchase a computer with at least 80 GB to 100 GB of hard disk space. An expansion pack such as Rise of Nations: Thrones and Patriots requires 750 MB of space, while an online role-playing game such as City of Heroes requires a minimum of 2 GB. To ensure the hard drive is a fast one, look for 7,200 RPMs (revolutions per minute) and 8 MB of cache.
Sound card and speakers. When it comes to audio, today's games may feature a number of bells and whistles—such as 7.1 surround sound that splits audio into seven different tracks, plus the bass via the subwoofer. But don't bother investing in one of these audio cards if you're counting your coins. A regular Creative Labs Sound Blaster Live! or Sound Blaster Audigy card is all you need to deliver great-sounding music, voice, and effects in titles such as Halo: Combat Evolved or Star Wars: Battleground. Pass on the 5.1, 6.1, or 7.1 surround sound set-up if you're watching your wallet, and instead choose a PC with a good set of 2.1 Klipsch speakers.
Disc drives. Many PC manufacturers sell desktop computers with DVD burners or multiple CD or DVD drives. However, all you need is a single drive configuration that plays DVDs and CDs, and records (or burns) onto CDs. These are referred to as a DVD/CD-R/RW combo drive. As for speed, expect a 16X DVD reader and 48X CD-R/RW drive to burn discs. So, unless you come across a good deal, forget about a DVD burner for the time being.
Monitor and chassis. Choosing one of those snazzy flat-panel monitors may save space on your desk, but it can really eat up one's budget. Therefore, even though they're big n' bulky, choose a 19" CRT monitor instead. Plus, while the thin LCD screens look attractive, often the refresh rates are not fast enough to render a game's graphics smoothly. Look for a rate of 75 Hz for a monitor up to 17 inches, and 85 Hz for a larger monitor. When it comes to your desktop computer's chassis, a mini-tower or mid-tower is fine, but be sure there are a couple of extra slots at the back (PCI or AGP) so you could add more components, if so desired."
Good luck
Regards,
Korrupt