As long as you stick with Asus, Asrock, Gigabyte or MSI brand boards you should be in ggod shape. Just make sure the board you choose supports the six core CPU's and is a DDR3 board. USB 3 and SATA 3 (6 Gb/s) support would be a good idea also as its more future proof. The most important parts in any PC are the memory and power supply so do not skimp on either. For memory I stick with Corsair or Crucial when possible. For Power supplies Corsair or Seasonic. If you can give us an idea of what you want to use the PC for, how much you have to spend and a list of the components you were looking at we can be more specific with recommendations.
Main Box*i7 930*GA X58A-UD3R R2*3x4 gig Patriot DDR3 1600EL*EVGA GTX 460 1 gig*Intel X25-M G2 80 gig*WD Green WD20EARS 2 TB*ASUS DRW-24B3LT*Samsung SH-S223L*Corsair AX750 PSU*Rosewill Challenger case*Windows 7 Ultimate 64 bit SP1