http://www.newegg.com/Product/Product.aspx?Item=N82E16813131142 - ASUS P5N-E SLI LGA 775 NVIDIA nForce 650i SLI ATX Intel Motherboard - Good board with room to upgrade in the future.
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115014 - Intel Core 2 Duo E4400 Allendale 2.0GHz 2M shared L2 Cache LGA 775 Processor - Dual Core is a must
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150228 - XFX PVT84GUDF3 GeForce 8600GTS 256MB 128-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card - Should do just fine for what you want to play and its DX10.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145023 - CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 675 (PC2 5400) Dual Channel Kit Desktop Memory - You could live with 1 gig but may as well go with 2 with games like Crysis on the way.
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136073 - Western Digital Caviar SE16 WD5000AAKS 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - Good size hard drive for when TSTT finally roll out Blink and the real downloading start.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153052 - Thermaltake Purepower W0100RU ATX 12V 2.0 500W Power Supply 115/230 V - Might need someone else to advise you on the powersupply,
And the case could be whatever kinda case style you like, just make sure it big enough and cooled properly.
$4716TT without a case if bought from Newegg, you'll need to add in shipping and such though.
Something like this should handle everything you throw at it and will last you a good while, could always upgrade later on without having to buy a whole new pc again.
Any questions just ask.