Then why did you point to energy needed for the idle and low load to counter the average power consumption ? Cause it make no sense considering you latest argument.
And remember that at the start start of all this I was speaking of power efficiency, not performance, has I was comparing a 55W TDP 2.7Ghz celeron, which to be about the intel product you can get for about $50 (since he was suggesting a pentium, but they start around $65), to a $75 35W TDP 2.6Ghz Pentium, which I think was more worth it if you were trying to save money, for a lowest end gaming PC, has it would more then likely consume both less energy while idle and under load.
The best really depend on whatever you spend most of system spend most of it time in idle/low load or in heavy load, which most home computer don't, including a gaming PC, has it most likely see it fair share internet, video and lot of game that are mostly GPU load not CPU. So I am mostly always gonna suggest the higher priced lower TPD CPU over the lower price higher TPD CPU of somewhat close performance, and if the guy got real money to invest, suggest undervolting the best cpu he can buy instead, if want to save power. (but that last case don't really apply when speaking of Celeron and Pentium =p)
Correct graph with comparison of power consumption has to be done in way that you can deduce total power consumption in Watt-hours during constant time e.g. 8 hours while doing same tasks.
You can compare total consumption if you know that machine is idle 3 hours and 5 hours is used for video watching.
Average power consumption graph at silent PC is assuming 50% of time on heavy load. If fast CPU encodes videos 4 hours it will encode more videos than slow CPU.
If same tasks are done slow CPU spend more % of time on heavy load than fast CPU which means constant split 50:50 is wrong.
$75 35W 2.6Ghz Pentium G2100T and G2020T are tray/OEM only which means limited availability and warranty.
You can get 35W CPU by underclocking and undervolting of 55W CPU, but it will mean 1W / 2W / 3W lower power in idle / low load / full load in average.
2W lower power means about $2 lower bill per year.