Ok, lets face it. Those kind of data are not reliable when we talk about FOSS software, and asking what is the most popular/downloaded/used/insert-counter-here (IMO the first and third are very opinion based) is not reliable. I'm all out to help people, just not in the main site. They could ask in chat, in a Forum, in Discourse, elsewhere they could get a hand-help, but asking us for raw or processed data (which is ultimately what the questioner will want) wouldn't fit the autoritaviness model of the site.
Again, I'm not trying to diagre for the sake of disagreeing, I'm worried about what this Pandora Boxes could bring to us and I sincerely don't want us scoping this kind of questions.
(BTW, I know that there was a optional package called popularity contest, which would provide some insight, seems that USC offers something similar but I wouldn't take that data as a source of information for serious investigation)