Please forgive the cut and paste. I just bought this combo for my next pinball simulator:
Intel Core i3-2120 BX80623I32120 Processor - Dual Core, 3MB L3 Smart Cache, 512KB L2 Cache, 3.30 GHz, Socket H2 (LGA1155), 65W, Fan, Retail (I69-0212)
$114.99
Ultra LSP750 750-Watt Power Supply - ATX, SATA-Ready, SLI-Ready, 135mm Fan, Lifetime Warranty w/ Registration (ULT-LSP750)
$69.99
GIGABYTE GA-Z77-DS3H Intel 7 Series Motherboard - ATX, Socket H2 (LGA1155), Intel Z77 Express, 1600MHz DDR3, SATA III (6Gb/s), RAID, 7.1-CH Audio, Gigabit LAN, USB 3.0, PCIe 3.0, CrossFireX Ready (G452-2366)
$104.99
Corsair CMZ4GX3M1A1600C9B Vengeance Desktop Memory Module - 4GB, PC3-12800, DDR3-1600MHz, 9-9-9-24 CAS Latency, Intel XMP Ready, Unbuffered (C13-5722)
$25.37
I got a couple of GTS250 video cards that I'm going to use in it. I'll upgrade the video card(s) if I have to.
Buying a good computer isn't cheap, but if you don't need nfl blitz and hoggy games, you can get by with a P-4 2.0 GHZ curbside find.