As a general observation, I think the "RAM is cheap" consideration is an important one: I've been struggling along with 6GB for years and of all the upgrades I've made recently, hiking that up to 32GB has made a huge difference. Okay, that amount is probably overkill for any individual game at present but it's useful when you're running a bunch of mod tools at the same time; and 6GB really isn't enough for most current games, it seems.
