The answer to your question depends on what you wish to wish to do with your system, and is a matter of opinion anyway.
For what its worth, my opinion is based on :
1) A board that uses DDR memory as it has the fastest performance for the AMD platform, and isn't too expensive.
Also my guess is DDR will gradually replace ordinary SDRAM, initially on high performance systems, then eventually on the rest.
2) I favour systems using AMD 760 chipset which supports DDR memory.
3) As I am not aware of any motherboards that use the AMD 761 Northbridge and 766 Southbridge then I believe the next best thing to be AMD 761 Northbridge with VIA 686B Southbridge
The best performing combination of the above from reviews I have read is the Asus A7M266.
I purchased this motherboard in early Feb 2001 and have not had any problems to date. I am using it with a 1.2 Athlon C .