For mATX, I like Biostar as well. I've used an M7VIG Pro on my kids PC (supported DDR & Sdram and I was swimming in Sdram at the time). Made a nice little PC.
KM266 chipset
AGP slot for future upgrades
Onboard Lan
Onboard S3 ProSavage video
6-Channel audio
200 / 266MHz front side bus
M7VIG Pro
I used an M7NCG on a friends build. Nice board.
nForce 2 chipset
AGP slot for future upgrades
Onboard Firewire
Onboard Lan
Onboard GeForce 4 MX video
6-Channel audio
200 / 266 / 333MHz front side bus
M7NCG