Looking just a processors, and on your budget I would say stick to the top line of each technology, i.e. either the E5200, E7300, or Q8200. The small increase in processor speed within each processor series is not worth the price increase (e.g. E7300 2.66Ghz for R999 versus E8600 3.33Ghz for R2500 = 250% price increase for a 25% performance increase - real benefit in gaming will be far less).
R 589.00 Intel CPU E5200 Pentium Dual Core LGA775 2.50GHz 800Mhz FSB 2MB Cache
R 699.00 Intel CPU E5300 Pentium Dual Core LGA775 2.60GHz 800Mhz FSB 2MB Cache
R 799.00 Intel CPU E5400 Pentium Dual Core LGA775 2.70GHz 800Mhz FSB 2MB Cache
R 817.11 Intel CPU E6300 Pentium Dual Core LGA775 2.80GHz 1066Mhz FSB 2MB Cache
R 999.00 Intel CPU E7300 Core 2 Duo LGA775 2.66GHz 1066Mhz FSB 3MB Cache 45nm
R 1,123.59 Intel CPU E7400 Core 2 Duo LGA775 2.80GHz 1066Mhz FSB 3MB Cache 45nm
R 1,299.00 Intel CPU E7500 Core 2 Duo LGA775 2.93GHz 1066Mhz FSB 3Mb Cache 45nm
R 1,286.72 Intel CPU E7600 Core 2 Duo LGA775 3.06GHz 1066Mhz FSB 3Mb Cache 45nm
R 1,585.00 Intel CPU E8400 Core 2 Duo LGA775 3.00Ghz 1333MHz FSB 6MB Cache 45nm
R 1,775.00 Intel CPU E8500 Core 2 Duo LGA775 3.16Ghz 1333MHz FSB 6MB Cache 45nm
R 2,440.00 Intel CPU E8600 Core 2 Duo LGA775 3.33Ghz 1333MHz FSB 6MB Cache 45nm
1,585.00 Intel CPU Q8200 Core 2 Quad LGA775 2.33GHz 1333Mhz FSB 4MB Cache 45nm
1,775.00 Intel CPU Q8300 Core 2 Quad LGA775 2.50GHz 1333Mhz FSB 4MB Cache 45nm
1,898.87 Intel CPU Q8400 Core 2 Quad LGA775 2.66GHz 1333Mhz FSB 4MB Cache 45nm
2,085.00 Intel CPU Q9400 Core 2 Quad LGA775 2.66GHz 1333Mhz FSB 6MB Cache 45nm
2,465.41 Intel CPU Q9550 Core 2 Quad LGA775 2.83GHz 1333Mhz FSB 12MB Cache 45nm
2,986.04 Intel CPU Q9650 Core 2 Quad LGA775 3.00GHz 1333Mhz FSB 12MB Cache 45nm
7,999.00 Intel CPU QX9650 Core 2 Quad Extreme LGA775 3.00Ghz 1333Mhz FSB 12MB Cache 45nm
10,999.00 Intel CPU QX9770 Core 2 Quad Extreme LGA775 3.20Ghz 1600Mhz FSB 12MB Cache 45nm - No Fan
11,367.48 Intel CPU QX9775 Core 2 Quad Extreme LGA771 3.20Ghz 1600Mhz FSB 12MB Cache 45nm - No Fan
R 2,599.00 Intel CPU i7-920 Core i7 LGA1366 2.66GHz 4.8GT/s QPI 8Mb Cache 130W 45nm
R 5,059.00 Intel CPU i7-940 Core i7 LGA1366 2.93GHz 4.8GT/s QPI 8Mb Cache 130W 45nm
R 5,212.64 Intel CPU i7-950 Core i7 LGA1366 3.06GHz 4.8GT/s QPI 8Mb Cache 130W 45nm
R 9,399.00 Intel CPU i7-965 Core i7 LGA1366 3.20GHz 6.4GT/s QPI 8Mb Cache 130W 45nm
R 9,298.22 Intel CPU i7-975 Core i7 LGA1366 3.33GHz 6.4GT/s QPI 8Mb Cache 130W 45nm
