Seriously, if you want it to last, get a dual core Sandy Bridge (the i3's) or even a quad core Sandy Bridge if your budget can handle it.
It's really like, the fastest thing out there right now. (consumer processor wise)
EDIT: That combo looks fantastic. Case looks fugly, though. $5 extra.
DVD: http://www.newegg.com/Product/Product.aspx?Item=N82E16827135204 $22 ($7 shipping)
Case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811129042&cm_re=antec_300-_-11-129-042-_-Product $60 Antec 300
CPU: http://www.newegg.com/Product/Product.aspx?Item=N82E16819115073&cm_re=Core_i5_2500-_-19-115-073-_-Product $209.99
RAM: http://www.newegg.com/Product/Product.aspx?Item=N82E16820231274&cm_re=4_gb_ddr3_1333_Ripjaws-_-20-231-274-_-Product $45 4GB G.Skill Ripjaws
PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817371016&Tpk=Bp550 $45 after rebate Antec BP550 500W Modular 80 Plus PSU
MoBo: http://www.newegg.com/Product/Product.aspx?Item=N82E16813128476&cm_re=UD3-_-13-128-476-_-Product $123 GA-p67a-ud3
HDD: http://www.newegg.com/Product/Product.aspx?Item=N82E16822152181&cm_re=Samsun_Spinpoint_f3-_-22-152-181-_-Product $50 Samsung Spinpoint F3 500 GB | Caviar Blacks are popular but this is less expensive (and benchmarks higher with what I've read). I picked 500 for you because 1 TB is overkill for gaming.
GFX: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127519&Tpk=GTX%20460%20twin%20frozr $135 after rebate ($8 shipping)
Works out to be $705. You could even go for the Core i5 2400 to drop it under $700: http://www.newegg.com/Product/Product.aspx?Item=N82E16819115074&cm_re=Core_i5_2400-_-19-115-074-_-Product Won't be much of a difference other than a .2 GHz change.
This is what I'm getting this summer, except my case will be the Storm Scout and I'm getting a 1TB HDD for music stuff. Don't need all the space now, but will eventually.