I love franchises. When I get into a story and character, I like to see them continue. Investing my time and energy to meet new characters just to have it end in 90minutes...not fun for me. Which is why I enjoy tv series more than movies lately. So....i've seen a ton of the franchises out there, and love that they keep doing more and more movies.
In fact for the longest time I couldn't understand why they didn't make more Star War movies - and I'm not even much of a fan. But gigantic success, huge fanbase....it's just common sense, keep going?
From the Wikepedia link posted in OP - I've watched at least 1 movie (and often, all of them) in the top 40 listed by gross $$. The first one I never saw is Conjuring.
If you go by movie count, here are the ones I never watched any of:
Madea (then again, I think it's possible I saw one, not sure if it was in that series though)
Conjuring
Alvin and the Chipmunks
Lego
Also never saw Pokemon.