I'd pesonally prefer an nForce4 chipset
I just got myself a brand new amd64 and mobo using the nforce4 chipset and i must say i am dissapointed in it. The main problem with the nforce4, is that the PCI perfomance of it sucks. It was for example impossible to get my hardware mpeg2 dvb-s "nexus-s" card to work because of these issues. Whenever there is slight movement, the picture gets completly corrupted unless you resize the picture to a tiny window. I first thought it was my particular mobo "gigabyte" that was the problem, but it happens to be that any mobo using the nforce4 chipset has this issue. :-( Adjusting the pci latency wont solve this issue either and the corruption is worse than i experienced on my old k6-2 with a {bleep}ty via chipset.
The same board worked just fine on my old via kt133a and the kt333 and even my really old compaq pentium 3.
I can use the card somewhat when using software decoding instead of the built in hardware decoder of the card.
I think this will affect any similar cards like tvtuners and other dvb cards as well.