I'm using the ECS A780GM-A Black Series. Been good to me. Very stable, has all the components/features I need. I have my Phenom 9600 BE oc'd to 2.7ghz right now. Be warned though: it does not seem to like increases in the FSB. Get a BE cpu if you plan on oc'ing and do it with the multiplier.
I've owned the ECS A780GM-A Ultra AM2+/AM3 (AMD 780G HDMI ATX AMD Motherboard Black Series) for a little over a week now (picked it up during a Newegg sale), it has been rock solid stable. All six (6) x SATA ports are functional, using AHCI too! The chip I'm using is an AMD Athlon X2 7850 Black Edition Kuma 2.8GHz processor and it's a beast: it tears through compiles of glibc and gcc under Gentoo. This is my second ECS board and am very pleased with the build quality. There's no reason to be hesitant toward this manufacturer: I went through two really expensive (had to RMA them both for defects) Gigabyte boards before deciding on this one. And Gigabyte is pretty much a household name at this point, right up there with ASUS. I say look no further! This board performs, and I love that it has the AM3 upgrade path, in case I decide to replace the chip at a later time!