Everybody is talking about 1, 6 and 11 being the best channels. But nobody is differentiating between 802.11b, g or n.
I found this illustration, which shows the channels that don't overlap for the different kinds of Wi-Fi. It's from the German Wikipedia, so it contains channels 12, 13 and 14 too. And these are for me, as I live in Germany, possible channels to use.
What I didn't find was an explanation of which channels are best to use if more than one kind of Wi-Fi networks exist in the same area. In my case there are both 802.11g/n networks as well as 802.11n-only networks, some using 20 MHz-wide channels and some using 40 MHz-wide channels.
So what are the best channels to use, if the Wi-Fi networks in the area are using both 20MHz and 40MHz-wide channels?