Well, for better or worse, the DCEU has more or less ended after an (almost exactly!) 10 year run. Technically, there's still Aquaman and the Lost Kingdom, but right now it's a bit ambiguous which continuity it specifically slots into - anyway, once it's out, we can consider it a coda. But The Flash did seem like an ending to the DCEU, so I felt this would be a good time to do a ranking.
I've ranked everything apart from Peacemaker, which I haven't watched yet. Once I get around to doing so, I might edit this post to include it.
From Best to Worst
Man of Steel
The first is still the best. Honestly, I don't think any other DCEU film really topped the sheer potential of MOS. Love it or hate it, this movie redefined (or at least tried to redefine) Superman for a new generation and too date is part of some rather heated discourse. Long after the rest of the DCEU is forgotten, MOS will continue to be the subject of furious debates. It has truly earned its place in cinematic history in my book.
Wonder Woman
Also a serious contender for best DCEU film. The movie, and Gal Gadot's performance, will no doubt define Wonder Woman for generations the way Donner's movie defined Superman. The WW1 setting really made this movie, which could otherwise have been a pretty generic superhero origin story, stand out. The scene of Wonder Woman walking across No Man's Land alone is an iconic cinematic moment.
Aquaman
The film was part of the DCEU's 'MCU-lite' era, but as far as that goes, it was pretty darn good. It showed that the DCEU could have had a future beyond Snyder's original (admittedly polarizing) vision. And Momoa's Aquaman is always a joy to watch.
Batman v Superman: Dawn of Justice
It's not a perfect film by any means, but it had ambition - even if that ambition was a bit too lofty for vast sections of the audience to handle. Moreso than even MOS, this felt like DC heroes in a grown-up world.
The Flash
Despite all the baggage it carries, this is truly a solid film - one that perfectly balances a light-hearted tone with some serious world-ending (and multiversal) stakes. It's a nostalgia-fest for sure, but it also is a character study with some serious emotional depth to be found amidst the CGI. Plus, Michael Keaton as Batman...Nuff said!
Zack Snyder's Justice League
I wish I could rank this higher, but frankly it's really more a post-mortem on what could have been (much like the Superman II Donner Cut). It's not as though Snyder could seriously have released a 4 hour film in the theatres, so this isn't what we would have got had he stayed at the helm of the theatrical cu. But still, it's a highly ambitious film...one that admittedly crumbles a little under the weight of that ambition.
Shazam!
A nice fun film. Again, it showed a potential path for the DCEU post-Snyder, one that they never really capitalized on.
The Suicide Squad
Pretty solid effort by James Gunn, and a definite improvement over the first (the theatrical version we've all seen anyway). It remains the only DCEU film to have spawned a spin-off TV show, so there's that too!
Black Adam
It does feel like a generic "would have been great if it released in the 2000's" kinda film, but a pretty good one at that. I mainly love it for the JSA, and that cameo at the end. But yeah, it ended up changing the hierarchy of f#ck all!
Birds of Prey
A lot of people dislike this film, but I found it fun and loved its vibe. Harley Quinn is totally on point here but so are the other characters (admittedly, I totally understand why Cassandra Cain fans would be p#ssed though!)
Wonder Woman 1984
Another film I'll defend to the death (okay maybe not that much). A neat and fun throwback to the Lynda Carter show, the crazy Silver Age comics, and the Lester Superman films.
Justice League
It's not that in isolation the theatrical JL is a bad film. But it totally betrays the potential of Snyder's original vision and feels pretty overtly like Avengers-lite. I mean, there's a reason why fans spent years passionately campaigning for the Snyder Cut. As someone who spent most of my life waiting to see a JL film on the big-screen, it was one big disappointment.
Suicide Squad
The film had a great vibe and some neat characters, but not much of a narrative. Joker was totally wasted. So unfortunately it ranks pretty low...maybe someday an 'Ayer Cut' could rank higher?
Shazam! Fury of the Gods
I honestly didn't think this would end up ranking as the worst of the DCEU for me, since I actually kinda enjoyed it in the theatre. It was a fun watch, but lacking in even the semblance of any substance. That's okay I guess...you need Fury of the Gods in order to be able to appreciate an MOS!