I game quite a bit, so I would like to throw in some stuff real quick.
A) Graphics:
GeForce4 MX - Don't bother. When it comes to gaming you have to have a solid system, from what I have seen of the GF4 MX series, they generally rate down with the good GF2's. I ran a Gainward GF4 Ti4200 for a year without a single problem, and it is still a solid card if I had a system to put it in. I also had it overclocked the majority of that time. As for edemieres comment on Gainward cards, I haven't heard that one, I have seen a lot of good reviews for Gainward cards in general and recently when my father was purchasin a latest and greatest machine that wouldn't need heavy graphics, I pointed him to the Gainward Ti4600 as a card that will perform well and last a while.
ATI - I have seen some very mixed reviews on the ATI 9600 series, everything from "greatest performance for price" to "why bother, the 9500 performs as well or better". I currently have a system running a 7000 (non-gaming) and a system running a 9700 pro (gaming). The 9700 pro actually out benchmarks my overclocked Ti4600 by just a little, but head to head the 9700 is much better than the Ti4200.
Newest and Greatest games - starting in September (or possibly a little later, possibly postponed) directx9 games are going to start hitting the market with the release of Half-Life2. While it is entirely possible to do the directx9 rendering by software, or just not have it at all, die hard gamers are going to want cards that have directx9 capabilities built in. This means a GeForce FX series card or ATI (9500?)/9600/9700/9800 preferably pro or all in wonder versions.
CPU: My gaming system is actually running on as P4 right now, but I don't have a real preference based on games. Based on over-clocking I like the P4 C's (800 fsb) because of the higher front side bus.
Motherboards: It's not necessary to have a motherboard that was released this week. A motherboard that was built to support the processor your putting on it is adviseable, because I've found they run more stable in the long run than a board that can accept a certain processor after a certain number of BIOS revisions. For example, I just built an AMD XP1800 system based on the Asus a7v133 motherboard because I wanted a cheap system for my sister. It only supports the XP processor after BIOOS revision 7 so it was a little tricky to get it to boot the second time. Much trickier than 95% of the population would have the patience for.
The el cheapo system I just built: < $250
Case: Something moderately cheap from NewEgg, 2 intakes, 3 exhausts, 350W PSU
Motherboard: Asus A7V133, BIOS v1010b
CPU: AMD 1800 xp
Graphics: ATI 7000
RAM: 2x128Mb PC133, Kingston Value
Fans: 2 80mm Fans, 2 92mm fans
The rest was moved from an older system, including CDROM, CDR, Sound, Modem, Wireless NIC, floppy, 10Gb HDD
Compared to what will be the next version of my gaming rig, approx upgrade price $900:
Case: Enermax server case
Motherboard: ASUS P4P800
CPU: P4 2.6C (800fsb)
Graphics: ATI 9700 Pro
RAM: 2*256Mb DDR400 Corsair LL (low latency - CAS<2)
Everything else already on hand.
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Motherboard companies I like:
Giga-Byte, ASUS, and Abit
Graphics Cards I like:
ATI 9500 pro, 9700 pro, 9800 pro made by ATI or Saphire
Nvidia Ti4200, 4600 made by gainward
I'm not up to date on the FX series, i lost some interest after the issues with the first couple FX flops
RAM Manufacturers I like:
Corsair, GeIL, Crucial - I generally prefer CAS 2 or corsairs new LL (Low Latency)
Cooling Solutions:
Cooling can be the difference between playing a game until the wee hours of the morning or having it crash after 20 minutes of play time. Generally stock coolers will perform ok if you don't plan on overclocking the system, occasionally in a gaming system it is necessary to buy an aftermarket cooling solution because the stock cooler wasn't made to handle long hours of high CPU and Video utilization.
A case should have a minimum of 1 front intake and 1 rear exhaust if your going to game with it.
Hifher end Pentium retail Heat Sinks that come with the processors are actually decent (copper core), AMD's may need to be replaced.In either case I have had good results with Thermaltake HSF's.
Case fans: generic fans will work, albeit not as well and more loudly, just make sure you have good airflow, ie neaten the cables inside with zip-ties/electric tape/cable sleaving and don't block the vents. I prefer aftermarket fans for my cases, generally of the pretty light up variety

Video Card cooling: The GPU (Graphics Processing Unit) for the graphics card can get pretty toasty, but every card comes with some sort of cooling solution. Generally these are adequate, I found the Gainward Ti4200 Video cooler to actually perform almost as well as an aftermarket one I purchased but the ATI 9700 cooler barely kept the video card from over heating and crashing a game. In either case,as long as no one is planning on overclocking you should be good with the stock cooler.
Anyways, justa couple thoughts while I browsed the thread
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