The contemporary chipset market has become very much different from what we remember. There are much fewer active players left, and those who are still there offer their solution without any real alternatives to consider. Take for instance, Athlon 64 platform. Thanks to the implementation of integrated memory controller in these AMD processors, the role of chipsets in today's systems has become less important.
In the old times of Socket A processors the chipset developers could really compete with one another using a pretty significant argument such as overall system performance. Now that the memory controller has been moved into the CPU, the influence of the system chipset on the overall platform performance has almost vanished. We can even claim that if a given chipset doesn't suffer from any evident issues with the implementation of graphics and other busses for external equipment, then its performance will be exactly the same as that of any other alternative core logic set out there.
The second thing users may potentially care about in the system chipsets besides performance is the set of features it supports. Different chipsets offer support for different number and types of ports for hard disk drives and other external devices, may support faster or slower data transfer protocols or different work modes for the integrated controllers. However, these differences can hardly be regarded as significant, also. Finally, you can always eliminate certain chipset drawbacks with external controllers, which have become an irreplaceable part of every mainstream and high-end contemporary mainboard.
In other words, it is more important these days to pay special attention to the mainboard manufacturer's reputation and the features of the particular mainboard model, rather than to the chipset it is actually based on. And speaking of the chipset makers, who do best of all in the today's market, these are the ones with the smartest marketing policy, most attractive chipset pricing for the mainboard makers and on-time introduction of the new interfaces and protocols support.