i5 2500k is the better bang for buck vs i7 2600k. It OC's better and is just as fast, if not faster, in games for less cheddar.
Too bad the chipset intel launched with them have all been recalled and the replacements won't be on store shelves till April iirc.
That AMD 6950 2gb is a great value as well, can easily update the bios to the 6970 and you get a $350 card for $250. Lacks PhysX, but that shouldn't really be a deal breaker. If you need nVidia, I suggest going with the GTX 560 TI, great card and fantastic overclocker. Multi GPU is a waste for games like Civ and SC2. If you're planning on playing high end FPS games like the upcoming BF3, then it may be something to think about when purchasing the mobo (Two x16 PCIE 2.0 slots will be a must).
8gb DDR3 has become the norm with rock bottom ram prices. After rebates you can get 4gb x2 for $60.
Don't skimp on the PSU. Get Seasonic, Corsair, higher end Antec, etc. Modular is the way to go, reducing cable clutter by only connecting the ones you actually need. Building something along the lines outlined above you'll want at least 650 watts with a Bronze efficiency rating or higher.
SSD prices have been falling. You can get 60gb sandforce 1200 drives for $100. At that price you can get 2 of them and RAID for ridiculous speeds.
Think about cooling and your case solution. I'm planning on building my next system in the Silverstone FT02, due to it's positive airflow design and rotated motherboard set up. It also looks clean as hell. It will be a heavy ass beast when full (around 40lbs) but I don't plan on moving it much, if at all. The airflow in the FT02 is so effective with the new AP181 fans (penetrator lolz), you can Passively
cool an i7 980x using just a high quality CPU cooler and the case fans:http://benchmarkreviews.com/index.ph...1&limitstart=5
Fewer fans spinning means less noise coming from the case and the AP181 fans are now shipped with all FT02 cases.
AMD will be releasing their Bulldozer 8 "core" (APU) in Q2. I'm waiting to see the performance and price before making any final decision on platform (even though most mobo's will be limited to the Crossfire multi GPU option only).