The E8600 from Intel will be the flagship of the Core 2 Duo range until the end of its product lifespan. Intel have made a very definitive shift towards Multi-Core CPUs, with Quad-Core being the future as they see it, at least for the moment. The top range Core 2 Extreme processors now feature Quad-Core CPUs running at speeds that exceed 3Ghz, and while this will remain the fastest stock Core 2 Duo from Intel, Quad-Core chips will continue to be produced that will soon outstrip this speed.
So why a 5 star rating, and why consider buying the last of the Dual-Core range? The answer boils down to Value for Money - a favourite buzzword of corporate CEO and government official alike. A Dual-Core processor runs cooler in the case than a Quad-Core and generally speaking comes with a higher clock speed. Unless you're running multiple programs that are processor intensive and developed with a multi-core system in mind, you're not going to see an increase in performance. Coding issues mean that in some cases, a Dual-Core will perform better than a Quad-Core anyway. While the future is definitely going to see a move to more cores rather than higher clock speeds, for the moment, there's no great advantage for most users.
The E8600 is delightfully overclockable as well, which should please those who just can't resist squeezing the most out of their CPU. With Air Cooling alone, enthusiasts have comfortably overclocked to 4.5Ghz and upwards, some forums claiming to have reached a stable overclock to 4.9Ghz with air cooling. CustomPC got the chip up to 6Ghz with the assistance of some Liquid Nitrogen cooling - not exactly readily available, but an interesting experiment.
In addition to this, though, the E8600 sports a technical advancement that gives it an advantage worth considering - in this case a change in the chip stepping to E.0 which will soon filter through into the rest of the Core 2 Duo range.
With the new Nehalim chips on the horizon, anyone building a PC at the moment would be wise to consider this new addition to the Wolfdale range, particularly if you want a fast and eminently overclockable CPU.