As it turns out, today's systems need more than 640KB. Much more. We can all agree on that (as would Bill Gates, who adamantly claims he never said otherwise), though the exact amount depends on what you use your system for. A good sweet spot for a modern system is 8GB, which meshes well with today's top deal for a kit of G.Skill Ripjaws Series 8GB (2x44GB) DDR3-1333 Desktop Memory for $64 with free shipping (normally $75 -- use coupon code: [EMCXWXN37]). This dual-channel kit runs tight at 9-9-9-24-2N and features stylish heatspreaders.