Bionicle ended right as I was starting college, so I'd say that bionicle was the last line of my childhood. During college I did collect (and still collect) lego sets, I really enjoyed the LotR and Hobbit sets (Helms deep was one of the coolest) and I still grab the good star wars set. I got a bit into Ninjago, but I stopped following the story after the 2nd year with the serpentine. I haven't collected a new line the same way that I did with Bionicle.
However, now that there are more 18+ sets, I've been collecting more and more of those, I enjoy displaying those.