check the specs on the Gigabyte website - the more expensive board has three types of video connector on the back panel, it also runs crossfire at X16 and X8 versus X16 and X4 for the cheaper board. More expensive board has ability to support more USB ports. If you go to Gigabyte's site you can use the comparison tool to look at the features side by side. It appears the less expensive board is geared to a Home Theater PC as it has only an HDMI output on the board. Gigabyte is very good stuff - Asus is also very good - MSI not so much, but they have definitely improved over the past couple of years.
The Asrock Extreme3 has been suggested to me before. I've done a little research, and I've only been able to find a couple reviews. I'm considering it, but I'm still a little hesitant.
I take it that Asrock Extreme3 has a good reputation around here? How does it compare to the $160 Gigabyte board?