I've played all the LIS games and have been a fan of the series since the original released while I was in college.
For me, I think my ranking of the games is as followed:
Before the Storm
Life is Strange
Life is Strange 3
Life is Strange 2
Not including Captain Spirit because it's really more of a companion title and so short. It's a really close tie for me between the original LiS & LiS 3, as I really enjoyed both.
Before the storm was such a surprise for me and I really enjoyed the way they developed the characters & romance in that title, which makes it stand out for me.
Despite my love & enjoyment of the series, I really couldn't get into LiS 2. I played the whole game, but I struggled my way through it. I did not like the characters or the plot, and only finished it out of a hope that the ending would be worth it.
But I also really enjoyed the setting of True Colors, as well as the characters & story. I really liked Alex as a protagonist and her powers were interesting/different compared to the previous games.
I haven't seen much in terms of rumors about Life is Strange 4 yet but I'll certainly be playing it regardless, whenever it comes out.