We have three Asus boards here which all work
great using Slackware.
Asus P4PE (discontinued)
None of these are Nvidia nForce chipset boards...
You should also check the LinuxQuestions.org HCL
After reading Tim's post below I edited the above.
I should have said, "None of these are Nvidia nForce chipset
boards..." I originally left out the word "nForce"
Also search the forums to see if users have a lot of problems
with certain boards, such as nForce chipsets...