Which GPU / Video Card is more future proof?

I am building an I7 gaming machine and its going to be quite an investment for me, so I want to know which video card would be more future proof. An nvidia 285 has more and much faster memory than any ATIs, but the ATIs have dx11. I am getting a sli /crossfire capable motherboard with the intention of doubling up in a few years when I need an upgrade. Which of these will be better for gaming years from now? The bigger faster RAM or dx11?|||Heck if you want to build a computer to last you years from now, you might as well shoot yourself in the head. You are going with a quad i7 LGA1366 motherboard, but the thing is, by the end of this year the 6core 32nm i7 will be coming out. The 300GTX are coming out, the DDR3 is going to be up to DDR3 2800mhz next year and your old motherboard will not handle it. By this time next year they will be talking about DX12... And ole how everybody hates windows 7...|||get a crossfire board and an ati 5870 then crossfire later on.|||ATi has been producing higher quality and much better cards overall. The nVidia cards need more memory on board to properly function as less memory slows a computer down that has a nVidia card. This problem does not effect ATi cards. Consider investing in a ATi Radeon HD5870 as that will give you a good foundation for quite a few years.