Hrm...in my honest opinion, I would have to say Abit and Asus are very good mobo's. But you need to think of the following:
1. What are you going to do with it?
2. How high are you going to overclock?
3. How much are you willing to spend?
4. Do you need it NOW, or can you wait?
Honestly, I would wait if you could to get the Abit or asus. If you can't wait, then get the Gigabyte.