Re: Best chipsets
nForce series (nForce4, nForce 500, nForce 600 series) are typically the chipset drivers (Northbridge--as they are technically referred to) for Intel and AMD motherboards. The GeForce series (GeForce 6xxx, GeForce 7xxx, GeForce 8xxx) are referred to the level of GPU chipsets for Nvidia based graphics card.
I don't know if that's what you mean, but they both have "force" in them which can get confusing sometime for beginners. After awhile, it comes to you fairly easily.
SLI and things like that are video card technology patented by nVidia for dual GPU setups. Crossfire is ATI's video technology for the same thing (partnered with AMD now).
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?