Don't get socket 754 first of all - get socket 939. Second of all -- if you are building a new pc and/or upgrading your motherboard and video card, you may want to wait for the ATI X1600 series is released. It should be in stores in a month or two, it's already had it's paper release. Once it comes out you can compare it to other video cards in it's class to see which is the best for you. Now I am probably going to get flamed by some of the hardcore nvidia fanboys that patrol these fourms looking for anybody posting anything positive about ATI, but with that aside, I buy based on what really is the better product, not what I want to be the better product in my mind.
512MB of video memory is NOT a waste if you want to play F.E.A.R. on maximum settings at 1600x1200 without any lag or hitches. (assuming the card with 512mb is the top of the line card -- 512mb won't help a 6600 for example.)
so, umm, err yeah