I've found out about an awesome deal!, not the best performance/price on earth when you can get a sempron or dual atom instead, but it's the absolute cheapest mobo/CPU combo and for many people, 20 euros is a very meaningful difference.
http://www.ldlc.com/fiche/PB00104497.html
a 1.8Ghz VIA C7 with a slow DX9 IGP that decodes h264 and mpeg4, with a nice 800MHz fsb.
everything-is-soldered-but-the-memory-sticks makes a lot sense here as you may either use ddr2 or ddr3.
I appreciate the legacy I/O as you can use PS/2 mouse/keyb, laser printer and serial IR receiver for next to nothing in term of cost. real bummer is the lack of IDE but you can use a fast HDD or two and can always have external USB to IDE if needed.
PCIe 16x + PCI is the icing on the cake, you can use an old nvidia card + makeshift cooling, or a recent nvidia card, plus an old or recent sound card, or plug two NICs in and make a very powerful firewall using the crypto acceleration hardware.
if AMD Ontario mobos look like this, if possible with the same creative memory slots set up, that's about the perfect mobo as far as I'm concerned.