Re: Gaming at 1680x1050 GTX470 vs HD5850 vs HD5870
The 5870 is a much better card out of the 3, and just a tad slower than the GTX480.
If you're partial to Intel, the i5-750 or the i7-930 are some of the better choices from Intel.
If you want to save money, go with AMD. The new Thuban 6 core is out, which is a decent performer, from what small amount of benches I've seen, or there's the Phenom II X4 line. Ram will be totally dependent on what processor/motherboard you get, but usually OCZ Gold/Platinums are always a good bet.