The biggest unanswered question is whats your budget? I'll assume for now that you are looking to get something that performs very well without spending too much money, in which case this is the kind of build I'd go for;

Asrock P67 Extreme4 or Extreme6
i5 2500k or i7 2600k
GTX460 1GB / GTX560 1GB / GTX570 / HD6950 (take your pick)
8GB G.Skill DDR3 2133MHz RipjawsX
Any 1TB-3TB SATA2/3 HDD
Asus Xonar DX 7.1
Any DVD-RW / BD Drive that takes your fancy
Corsair HX1000 (future proof)

Cooling:

Coolermaster Hyper 212 Plus (its a excellent cooler, and at lest in the UK stupidly cheap)
120mm Coolermaster Sickleflow fans

That about covers you Don't let the current 1155 P67 issue put you off, its not as bad as it seems. I've tested SATA2 port3 (didn't try others) on my Extreme4 and it passed without any errors or warnings at all. The 2500k and 2600k CPUs also OC insanely well. Average OC seems to be about 4.5GHz @ 1.25v. If all that goodness doesn't tempt you, socket 1155 also appears as though it'll be around for a while. Ivy Bridge should be available on 1155 and 1155 will probably see some 8 core goodness as well down the road.