First Class is better...

First Class was much better.

Days of Future Past was much better, way better (in every way).

First Class is one of the best in the series, but Days of Future Past (THE epic of the series) is simply greater. Dis post... no.

I do.
First class was a good movie for anybody.

This one is good for fans, not everybody else.

Both are better than Apocalypse.

I fully agree. I felt that upon my first viewings of both films and after rewatching both again in the last few weeks, I feel exactly the same. First Class is simply the most purely fun and exhilarating of all the X-Men films. You can sense the joy in the characters as they embrace their powers. The James McAvoy/Michael Fassbender chemistry was at its strongest in this film, and the beach climax is one of the best setpieces in the franchise, which has had a pretty dubious history of ending their films in anti-climactic fashion.

Days of Future Past is a good movie with a compelling plot and excellent acting/characterizations, but here are my issues with the film: the prequel cast deserved more time on their own before the original cast got shoehorned in. The plot seems to exist for no other reason than to wipe out the ending of X-Men: The Last Stand. The action is less exciting than in First Class, without any genuine standout setpieces. In the original comic, the apocalpytic scenes set in the future were the highlight of the story, but in the film they're actually the film's weakest moments. The sentinels just don't come across intimidating enough (the CGI could have been better) and we don't get to learn much about any of the new mutants in the future so we don't care when they're killed by the sentinels.