What is the criteria for selecting the best Wi-Fi channel?

Out of the 3 non-overlapping channels (1, 6, 11) of the 2.4Ghz frequency on my wireless access point, I have a choice of selecting channel 1 which is the least used channel but it has 1 or 2 wifi hotspots with strong signals or I have the choice of selecting channel 6 which has more wifi hotspots than channel 1 but are all weak signals. 11 isn’t an option at all because it has much more users than 6. So it is a choice between either channel 1 or channel 6.

So what is the best channel to select on my wireless access point? A channel with weak signals but much more users on it? Or a channel that has much less users on it but has 1 or 2 wifi hotspots with strong signals on it? Will 1 or 2 stronger signals interfere much more with my wifi than a channel with weak signals but much more users on it?

Interestingly, when I set my wireless access point to auto wifi channel selection, it ends up selecting channel 1 which is the channel with the least amount of wifi hotspots but 1 or 2 strong signals. It would seem, then, that the wireless access point’s algorithm is more concerned about channel congestion than a strong signal interference.