Every DDR Athlon chipset has its issues. Some more than others, I guess. I guess your purchase decision depends on what problems might affect you or not. For example, VIA chipsets have receieved a lot of flack for alleged quirky PCI performance. A hardware site not too long ago did research and indeed did confirm this, also mentioning that Intel, SiS and ALi chipsets did not suffer from the same problems. I do not have the link handy, sorry...
Anyway, all I know is, a couple of years ago I went through two VIA MVP3-based motherboards that caused my Sound Blaster Live! audio to crackle when using EAX effects. When I replaced the motherboard with one based on the ALi Aladdin V chipset, the sound was perfect. The sound was also perfect on the SiS board I tested at the time (PCCHIPS M571). Is this a chipset issue? Well, since the only thing that changed in my system was the motherboard and appropriate drivers, it's easy to lean that way. Some might be tempted to accuse me of user error, and they might be right. But, I tweaked every BIOS option, updated the drivers and even reinstalled Windows 98 SE... nothing would make the crackling go away except for getting rid of the VIA board. The second VIA board passed from person to person, leaving a trail of destruction in its wake. On my Dad's computer, it caused his 3D-Revelator 3D glasses to go out of sync. On my sister's computer, it caused her audio to crackle and her first network card was incompatible with it (hard freeze). Slipping an ALi board in her system solved all of those problems.
This of course doesn't mean that ALi boards are perfect either. I had to run my TNT2 card in AGP 1X mode to avoid system lockups. However, since music production was more important to me, I thought I could sacrifice a little gaming speed (hardly noticeable, BTW) for perfect sound.
When my Dad got a VIA KX133 board, I noticed that the stability issue seemed better than the MVP3 board, but under intense graphical activity, I could still hear EAX occasionally crackle. I decided to avoid VIA boards at that point, and that was before I even began reading about the infamous 686B southbridge bug, not to mention the PCI performance issues.
Of course, then there's SiS, which seems to be doing fine with their SiS 735 chipset. It's unfortunate that the flagship product for this fine chipset is the sometimes flakey ECS K7S5A. The board itself has issues, which unfortunately the SiS chipset sometimes gets blamed for. One thing that might be the SiS chipset's fault is the fact that running certain PCI graphics cards on this motherboard will cause the audio to break up and crackle (even with the onboard audio). Now I have to find my Fiancée an AGP graphics card...
nVidia nForce I cannot comment on, since I have not cared to research it much, nor the AMD chipsets.
The original version of the ALi MAGiK 1 chipset was plagued by low performance, and I think ALi will have a hard time erasing this image, even though the new C-revision performs so much better. Although the ALi chipset works great with audio cards and nVidia graphics cards, there are some people having issues with certain video capture cards, and some Radeon users have complained about graphics corruption, but this only seems to be while overclocking. The latest AGP driver from ALi claims to help solve compatibility issues with many TV-tuner and capture cards, and not many people post problems with these boards anymore, so maybe it's fixed. Who knows... Overall, though, this chipset would be my primary choice. I have read many appraisals of this chipset for its stability, which is what I value above all in a system. Plus the fact that it's guaranteed to work with my sound cards is a nice plus
