With the Gigabyte boards you want the most recent revision of the UD3R series, unless you want onboard power/reset switches then you need to get the UD5R for nearly $100 more.
The Asus boards (except the Extreme) all have unique shortcomings. The Sabertooth has good cooling / low price but does not accommodate many video cards.
The P6X58D is a solid board that has two ethernet ports, space for three video cards, many power phases, good cooling, but cannot raid on SATA III and during boot it WILL look for a SATA III drive first - slowing the boot by several seconds. (My premium worked great till it recently died)
The P6X58D-E is like the premium but with slightly worse bridge cooling, one ethernet port, can SATA III raid, and is much cheaper.
The Rampage Formula (what I'm now using) is better than any of the above ASUS boards for SLI / Crossfire setups because you are supposed to use PCIEx16 slots 1 & 3 rather than 1 & 2. It comes with an extended bridge for this purpose. It can SATA III raid. But, it only has 8 power phases.
The Rampage Extreme is Asus's best board and the only con is high price.