Just a note, if you don't want to go the Intel path, and save a little money with AMD (I've heard that the AMD Phenom II X4 955 is all that you'd need for gaming currently on this forum multiple times), then you could go that route.
Western Digital Caviar Blue WD10EALX 1TB 7200 RPM 32MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-4GBRL
COOLER MASTER HAF 912 RC-912-KKN1 Black SECC/ ABS Plastic ATX Mid Tower Computer Case
CORSAIR Builder Series CX600 V2 600W ATX12V v2.3 80 PLUS Certified Active PFC Power Supply
ASUS ENGTX460 DirectCU TOP/2DI/768MD5 GeForce GTX 460 (Fermi) 768MB 192-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
AMD Phenom II X4 955 Black Edition Deneb 3.2GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor HDZ955FBGMBOX
MSI 870A-G54 AM3 AMD 870 SATA 6Gb/s USB 3.0 ATX AMD Motherboard
SONY Black 18X DVD-ROM 48X CD-ROM SATA DVD-ROM Drive Model DDU1681S-0B - OEM
That there's about $580 from Newegg if I'm not mistaken, but that wouldn't quite max Crysis...
Replace that GTX 460 with a superclocked GTX 560 Ti
and you've got a great gaming rig that WILL max Crysis at 4xAA pretty well for about $685. I think this
would be a good monitor for ~$150 per monitor.
Then Windows 7 Home Premium 64-bit is $100. here