First time building a desktop for my 10-year old kids. Primarily used for such games as Crysis, Spore, Half-Life, Battlefield, Halo games. Budget needs to stay around the $700 range. All parts are from Newegg:
Intel Core 2 Duo E7400 Wolfdale 2.8GHz 3MB L2 Cache LGA 775 65W Dual-Core Processor - Retail 119.99
GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard - Retail 134.99
G.SKILL PI Black 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail 54.99
CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Retail 99.99
Antec Nine Hundred Black Steel ATX Mid Tower Computer Case - Retail 109.99
HIS Hightech H485FN512P Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card 139.99
Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive 79.99
HP Black 20X DVD+R 8X DVD+RW 8X DVD+R DL 20X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 20X DVD±R DVD Burner 29.99
ASUS VH226H Black 21.5" 2ms(GTG) HDMI Widescreen 16:9 Full HD 1080P LCD Monitor 300 cd/m2 1000:1 (ASCR 12000 : 1) Built in Speakers 189.99
...well it's been a while since I took math, but its looking to me like you are way over budget. Are you asking for ways to cut down on your build without sacrificing quality? For $700 monitor included, I don't think its possible to build a computer to play crysis, most people would spend $300 or more on a GPU if they were planning on playing it.
Here's a build I made on another thread. If you get rid of the heatsink it will cut it down to $700. But if you keep the heatsink and overclock that cpu you will get alot more out of your money. Bump that cpu up to 3.5Ghz @ 1066 fsb (10.5 x 333).
btw, I added that case fan for the fact this case is set up to run 3x120mm case fans. It goes up in the front.