I haven't played in a while, and I got the Season Pass anyway, but the ones that were out before my display died are
* Automatron: Adds an extra questline and let's you build new robots to use as companions or to guard settlements. I liked that one, building robots was fun
* Wasteland Workshop: A bunch of stuff to add to settlements. The big one is that you can capture creatures and put them in cages, but first up you need to spend a pretty high-level perk to capture them, and secondly it doesn't do anything other than looks. I would skip this.
* Contraptions Workshop: Not sure if this was out yet, but I think so. Anyway, adds even more things to build in your settlements.
Far Harbor was not out yet. Generally these sort of expansions are the best ones from Bethesda, but I haven't played it. Should probably load up my old non-survival save and go exploring there.