sounds like your system is going to be focused alot on your actual monitor and graphics card. WoW honestly isn't the biggest thing as far as resolution, to play crysis you'll need atleast 2GB of ram. This is a budget build I have
This is a micro box, you can put in whatever graphics card you like, I'll configure another that's a reasonable budget.
I forgot to ask, dual core? quad core? Memory is cheap these days and are you going to use a lot of hard drive space? I suggest the 160 if it's going to be games, but, you can buy a 640 in two partitions for media, gaming and other programs.
Newegg.com - Intel Core 2 Quad Q6600 Kentsfield 2.4GHz 2 x 4MB L2 Cache LGA 775 Quad-Core Processor - Processors - Desktops
: Quad Core @ 2.6ghz that I find a lot of people use.
Newegg.com - GIGABYTE GA-EP45-DS3R LGA 775 Intel P45 ATX Intel Motherboard - Intel Motherboards
: Intel Mobo by GIGABYTE, lot of expansion on this one along with the PCI 2.0
Newegg.com - MSI P43 Neo3-F LGA 775 Intel P43 ATX Intel Motherboard - Intel Motherboards
: Intel Mobo by MSI, alternate with PCI 2.0 also
Newegg.com - Patriot Viper 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 1200 (PC2 9600) Dual Channel Kit Desktop Memory - Desktop Memory
: 2GB Patriot memory for the GIGABYTE
^^On the memory, you can change to yet another board to accommodate the MSI for cheaper^^^^
Newegg.com - Seagate SV35.3 ST3500320SV 500GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - Internal Hard Drives
: 500GB Sata Hard drive
Newegg.com - Seagate Barracuda ES.2 ST3750330NS 750GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - Internal Hard Drives
: 750GB Sata Hard Drive
Newegg.com - Rosewill RX750-D-B 750W ATX12V v2.2 & EPS12V v2.91 SLI 8800GTX SLI CrossFire Ready Active PFC PFC Power Supply - Power Supplies
: 750W PSU
Newegg.com - SAPPHIRE 100225L Radeon HD 3870 512MB 256-bit GDDR4 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards
:SAPPHIRE 100225L Radeon HD 3870 512MB 256-bit GDDR4 PCI Express 2.0 x16 HDCP
Newegg.com - Acer AL2216Wbd Black 22" 5ms Widescreen LCD Monitor with HDCP support 300 cd/m2 700:1 - LCD Monitors
:Acer AL2216Wbd Black 22" 5ms Widescreen LCD Monitor with HDCP support
At it's cheapest including the monitor, my subtotal is around 924.00 and some actual change. If you choose the cheaper motherboard then you can cut a few bucks off the memory and buy the 750GB drive.