The AMD "Zacate" E-350 series boards have much better performance at only modestly higher cost and power than the Atoms.  They're a bit hard to find with passive cooling, though, unlike the Intel Atom boards.  Still under 25-30W, though, which is nice, and usually under $100 for the mobo+cpu.  Video is much better than the Atoms, but it's still not going to hold a candle to even a modest "discrete graphics" solution.