DFI's boards are rock solid, HIGHLY overclockable, and compete/beat anything else out there on performance and reliability. Having said that, the Bios is very extensive and, unless you have at least a basic familiarity, the wide array of options could be a bit much to wade through at times.
BUT!! Before this thread turns into a commercial and/or popularity contest let me ask - What are your plans for your computer? Target overclock? Are you going to run Crossfire? Are you going for big Benchmark numbers? Or is this going to be an everyday working overclock?
For an everyday working overclock, any of the mentioned brands will serve very well.
If you're pushing for benchmark numbers is when you may want to start splitting hairs - Asking questions like, 'How many phase is the voltage regulation' and such.
Regardless of the brand, though. Personally I'm a fan of actual numbers in a Bios. Rather than + and - values like you would find on some boards, like much of Gigabyte's lineup. Call me stupid, or whatever, but when I want to set 1.21volts on something, I greatly dislike having to think "Well.. The standard is 1.8v, so +3 should be correct..". Screw that. If I want 1.21, I want to see 1.21 on the screen. And then when I boot and check settings via software, I want to see 1.21 there (actual output), as well. My DFI delivers that. ASUS, especially their enthusiast boards, are also fully capable of delivering that as well. Though I haven't built one recently.