http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=2000200022%20107191003%201071933047&bop=And&Order=PRICE&CompareItemList=N82E16813136044%2CN82E16813130136%2CN82E16813131291
I'm chopping for a 790 myself right now. Been tossing all these boards around all week. Wanna set it up with HD4850s Xfired. They got just about the same design. Few things, minor stick out. Both ASUS and DFI SATAs have that darn side port config. Drives some of us nuts. Other than that, they all OC pretty well. All take DDR2 800, and 1066 with AM2+ CPU. If you're down to just the two, I like the cooling on the NB on the MSI myself. I'm either getting that one or I'm gonna cheap out get a http://www.newegg.com/Product/Product.aspx?Item=N82E16813130172. I was down to the DFI, but sorta turned off by them HSs on the bridges.
It's a tough one dude, they're all referene design, so cost is a big factor too.
Penewah!
#1:MSI K9A2 790FX/AMD Phenom 9950BE125w OC 3.12/Xiggie120/Antec1200/HD4870 1GB ASUS/mushkinBlack 4GBDDR2800 /Sammy Spinpoint 640GB&320GB-SATA/PCPC 750W CF Silencer/ LITE-ON & ASUS DVD±R/Vista 64-bit/Dual 22" HannaG Mons/ WD My Book 500GB/Logitech X-530 70 watts RMS 5.1 Black Speaker System /#2:Biostar 780G/AMD 6000+x2/OCZ PlatRev2 2x1GB DDR2800 /Logysis-Acrylic/Vista/Ubuntu 8.1 / Corsair 550W PSU/#3:E8500/Gigabyte P45/HD4850/Xiggie 120/OCZ StlhStrm 700W, CM HAF case/OCZ Plat 2x! 1066