S1 of JJ is up there with the first half of Daredevil S2 as the best of the Netflix Marvel shows, IMO. I also enjoyed its second season, but it didn't have quite the same impact. (didn't see S3.)

I was pretty tepid on Luke Cage until S2 and its great villain. not sure if it's worth working through the first season if you aren't terribly interested to begin with, tho.

I made it one epside into Iron Fist before jumping ship.

as for The Defenders, totally forgettable (and a criminal waste of Sigourney Weaver), which is a shame. don't waste your time on it.