I feel like I enjoyed the X-Men movies more than most. I often think that not having read the comics gives me a big advantage with the movies as they have nothing to live up to for me, I can't think of one that I have disliked. Some I have enjoyed less than others, but they've all passed the time perfectly well.
The Last Stand is the only X-Men movie I don't like, but I actually really hate it.
I actually look at the first X-Men and Spider-Man trilogies very similarly. First movies were the best, second outings were very good but dragged a little bit and the third movies were franchise enders. Just gigantic dumpster fires. I can't tell which scene in a superhero movie best captured money being lit on fire, dark-emo Toby McGuire dancing on tables in Spidey 3, or the Joker dumping kerosine onto a pile of money before throwing a match onto it in TDK.
The new X-Men movies are quite good, Fassbender as Magneto is excellent. I think Apocalypse was hurt by the timing of its release more than anything else, though having your titular villain look as intimidating as Dowell Loggains didn't help.
I haven't watched most of them. I was never into mutants as a comic fan, and I wasn't all that impressed with the movies that have come out of them that I have seen, other than Deadpool. I haven't seen any of the Fantastic Four movies either, again, because I never really liked the comic characters.
Did you see Logan?
The Fantastic Four movies are all excrement, but aside from Dr. Doom, you're right there's not much to work with. Who cares about Thing in a universe with Hulk.