Start with the best motherboard + PSU you can afford initially. They will be the foundations for any future upgrades.
Components like CPU, RAM, Graphics Card, CASE etc can always be upgraded later as time and budget allow.
But if you skimp on the foundations, it can sometimes cost you more in the long run.
ie You buy a cheap yum-cha PSU and low end graphics card which work for now, but if in the future you want to upgrade your card only to discover that since you bought a cheap PSU, you'll have to replace that as well.
I'm not saying that you need the 'bells and whistles' models, but try to avoid the 'cheapest' simply because it is cheap.
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Systems by SmartEyeball
OS
8 Pro x64
CPU
i7 3770K 4.6GHz
Motherboard
ASUS P8Z77 WS
Memory
16GB G.Skill Trident X 2666mhz
Graphics Card(s)
x2 EVGA 780 Ti Superclocked SLI
Sound Card
SB X-FI Surround 5.1 PRO USB / ATH-AD900 Headphones
Monitor(s) Displays
x3 Dell U2410 / 58" Samsung
Screen Resolution
5760*1200/ 1920*1200
Hard Drives
2x Intel 520 240GB (RAID 0) * 2x WD Caviar Blacks 2TB (RAID 0) * 2TB WD Caviar Black * Sony Optirac DVD
Thermaltake Theron (Highly Recommended) + Razer Imperator
Antivirus
MSE
Browser
IE, FF, WaterFox
Other Info
GT Extreme V2 Sim Racing Cockpit + 40" LCD and K/B Mouse stand ▼
Fanatec CSR Elite Wheel + Clubsport V1 Pedals + CSR shifter/7G-H ▼Saitek X52 Pro ▼ TrackIR 5 Pro
Buttkicker v2 Seat Rumbler with Dedicated 5.1 and Sub Woofer attached to frame ▼
=
Bloody Big Grin
1.- State your budget for the build...last penny you can afford.
2.- As asked before... tell us if you have any parts that you have and might want to re-use.
3.- List the parts you have ready to go and the parts you need/want to buy
Once you do this, we may be able to come with some good deals for you. I like Intel/Nvidia, others may like AMD/ATI but, once we know what others suggest, we may be able to find the best prices for you.
I love nothing more than spending money that isn't mine... while still trying to find the best price possible
The first two both have pretty decent cpu's for the prices their going for. Also they both have blu-ray drives, great for hi-def action. personally I'd go for the core i3 system as it actually has a pretty nice selection of ports coming out of the back inc HDMI and optical. Also there's 2gb of ddr3 and the ability to take up to 8gb which is great. Now theres no card for gaming but its virtually garenteed that the core i system will have at least 1 PCI-E slot and maybe you could just make do while you save up for a card. Just to save your time I would call up Ebuyer (a highly reputable seller which I use to buy virtually everything techie myself) and ask if they know whether it has a PCI-E slot and also while you there, inquire about the PSU; asking for power output/wattage and wheather it has any PCI power leads (I wouldn't expect any more than one 6 pin). If they don't know you could just buy it anyway and check it out for yourself and if you don't like what you find, ship it back...distance selling regulations act is your friend.
Finally, system 3 there is a slightly cheaper system which does include a dedicated gfx card albeit a modest one. However with 1GB all to itself it should play some games on low/medium settings.
BTW all systems are without an OS, but maybe you already have one.
I don't know about the performace on these two though. I haven't built a comp in a while. The AMD side will be much cheaper though for CPU Mobo combination than Intel CPU Mobo combo
Edit: sorry just realized. I suggested quad core. You needing this depends on what you want to play and how long you want this system to be sufficient. Most games can be run with a Dual core CPU and a good Gfx Card. For staying power though I would suggest the quad core. This might eat up too much of your budget though.
My Computer
Computer type
Laptop
Computer Manufacturer/Model Number
ASUS G60-RBBX05
OS
Win7 Home Premium 64x
CPU
Intel Core 2 Duo P7450 / 2.13 GHz (2.29 with Extreme Turbo)
Memory
4 GB PC-6400 Hyundai (2X2) at 800Mhz
Graphics Card(s)
NVIDIA GeForce GTX 260M 1GB DDR3 VRAM
Monitor(s) Displays
16" LED Backlit
Screen Resolution
1366 x 768 on laptop 1600x1050 max res on 22" external mon