I built myself an i7 system... i7 920, Gigabyte X58 board, 3x 2GB G.Skill DDR3 with a Radeon 4870.
Quite an awesome system, really fast. Hopefully I won't have to upgrade for a while However, I'll be replacing
the Gigabyte X58 board with an ASUS P6T Deluxe and I'll replace the 4870 with something newer in a
few months as well. The specific X58 board I got, the X58-DS4 is very noisy and runs pretty hot (even
in a well ventilated case). I think the X58-DS4 Extreme offers better cooling.
I also have a Q6600 with 2x2GB OCZ Platinum RAM, it's a great system, but the i7 rig blows it away