This Tech Report review analyzes current CPUs from cheap to expensive to determine overall value. They also considered overall system value when doing the calculation, my like my own CPU electricity value analysis. I think they used more expensive components across-the-board than is quite realistic to consider (raising the value of performance), but they reached the same conclusion that I have. The Core i5 750 is the best all around value for price, performance, and electricity usage.
Last week, Fry’s sold a Core i5 750 + Gigabyte P55 USB3 motherboard for $210 after rebate. This is a phenomenal price because the Core i5 750 is $150-200 on its own. If you live near a Fry’s store, keep an eye out for this deal to pop up again.
One other thing to think about is that for regular home users that don’t do much more than web surf, you might consider a $150-200 Atom nettop. The max wattage for that system is 30w (idle: 20W), while the idle wattage for a current low-end Celeron/Athlon system will be around 60W-80W. That would save about $50/year on electricity if you leave it on 24/7, though you will be giving up performance.
This Acer Revo is a phenomenal overall value.