I also recommend the Sempron 140. I have yet to try it, but if I build another system, it will be using the Sempron 140. Currently, my main computer uses a Celeron 420 @ 2.66GHz/1333 fsb. With c1e it idles at 2.0GHz. My HTPC uses a Sempron Le-1100 barely overclocked to 2.0GHz, but spends most of it's time idling at 850 MHz. I've had a D 805, an e2160, e5200, X2 BE-2400, and X2 6000, but my needs were better served by single core CPUs, so I went back to my old stalwarts and have enjoyed the energy savings ever since.