Compiler & gaming machine?

My current machine is:
ASrock 939A785GMH main board
AMD64 3700+ San Diego core 2.2ghz (bench marked a little better for compiling)
2 gig ram
nvidia geforce gt 520
7200 rpm hdd
samsung 32" ips led back lit tv for a monitor

I just bought a Cooler Master Storm Stryker case. I just replaced a 19" crt with that tv. I only went with 1080p because I like to watch movies so I just as well get a good screen for bluray.

I'm a programmer and I will be using this to write software, some emulation, movies and some gaming. I am no avid gamer, but when i get in the mood its nice to have good graphics. I am quite accustom to building my own machines, I have never fudged on compatibility of bits or anything to that end. What I don't know is where I should really look for cpu and graphics. The current system will either be a second testing machine or I'll find someone local who can use it.

I was thinking I'd get a AMD am3+ 8core cpu, 990fx based mainboard. I like ASUS, Gigabyte sounds like a good company and my ASrock is a decent board too. I have not really fell in love with microstar, they are funky. I have heard a lot of good things about Intel Sandy bridge though, and I am not a purist. Probably Saphire for graphics or EVGA if i went Nvidia.

I will be playing borderlands 1&2 halflife 1&2, halo 1, runescape, star craft 2. I might try to see is mass effect 3 is for pc, I liked what I saw on my brothers ps3. I don't mind going a little high on graphics, but there's a point where its complete overkill and a waste. I will not be running 3d, ever. Also I will be compiling and doing some emulation. (like xp on top of linux) I hope to run this machine for 5+ years.

What advice can I get from you more experienced people?