P4 with Win7 32 bit - 2gig (DDR)
Core 2 Duo Laptop with Win7 64 bit - 2 gig (DDR2)
Core 2 Duo Gaming Rig with Win7 64 bit - 4 gig (4x1gig DDR2)
The first upgrade for my gaming rig will be more and better ram.
12Gb Ocz Gold 1066 in an i720 overclocked to 3.9Ghz (aircooled - Noctua fan) Win 7 Ultimate x64. I can have up to 24Gb but I can't afford that yet.