How much money are you willing to spend? Are you on a budget or is money not a concern?
Anyway, I don't have much personal experience (yet), but I've been researching mid-range Z68 boards lately and Asrock seems to be getting more favourable reviews than Asus and Gigabyte based on user feedback from NewEgg. Just something to consider.
Z68 Extreme3 Gen3 looks like a steal, I'm planning to get that one.