BTW niko084. I think the better midrange card is one that can play newer games on High, lower res, lower AA, rather than one that runs higher res/AA on Medium. So, yeah, I guess 8800GT 256MB, 3850 256MB are better midrange than say: 8600GTS 512 MB, HD2900gt 512MB, HD2900Pro 1GB, 8800GTS 320M and maybe even 8800GTS 640MB...
And you know why? Be prepared to know the truth. All those cards are slower at any resolution, because even if higher resolutions and AA need more memory, at the same time they need more shader and texture mapping power. And if you say but if X game uses bigger textures you need more Vram... Of course, but bigger textures need to be calculated too, so you need more TU power. And at this point in time seems that vram doesn't impact performance as much as GPU power does, at any resolution, so it's the GPU what it's bottlenecking the card not vram. And I have so many reviews out there backing me up that I won't bother posting a link. Google it.