I'm going with one of the AM2+ GIGABYTE boards, it's apparently solid for OC, though I don't do that. It has higher copper content in the power and ground layers of the PCB, apparently good for cooling and stability.
I got a GIGABYTE MA770-UD3. At that time I din`t have much cash to spend, just needed to get a new system with the cash I had at that point. However I think the mainboard is quite sweet. + the support 16ram is a big PLUS for I boxer I`d say.

The 945 is the next step up, I ordered one an hour ago for 225. It can be used in an AM2+ or an AM3 mobo and is compatible with DDR2 and DDR3.
Is the 945 compatible with AM3 mainboards? Since the 940 isn`t.