I'll take the challenge to name my top 10. I will assume you are referring to the ballgowns (because Cinderella dresses is a category that might include her rags/work dress and pre-rags dresses and/or wedding dresses).
10. Camila Cabello's Cinderella:
I've established many times how I don't like this movie and how it was a disappointment (me being a fan of Camila Cabello and being so hyped for a latina Cinderella in a full length feature film). However, if there's one thing I like, is Camila's costumes. I love the pinkish/white combination of colors and hues. Usually I'm not a fan of Opera gloves in general (my main reason the original 1950 Disney animated film and Brandy's version are not part of my top 10 ballgowns), but I feel this is a cool twist with them being more like complementary separate sleeves. Love the glitter all around too and it's a nice detail that her hair doesn't change much, as it is comfortable for her and still stylish and makes sense in both outfits.
9. Leslie Caron in The Glass Slipper:
For Leslie Caron they took the theatricality of costume on stage and brought it to life in this film. The pink flowers contrasting against the white puffy skirt is a nice contrast, and in general pink and white are a surprisingly usual combination for Cinderella's ballgowns in different media. Her short hair gives the look with the tiara a unique style and it looked very grand on screen at the time I imagine (as this is one of the first live action color films to adapt Cinderella). It is not ranked as high because it is canon that this look is kind of uncomfortable for her and I do believe that the ballgown in a Cinderella story should be comfortable and freeing for the main character.
8. Sarah Lelouch in Trois Contes Merveilleux:
The french anachronistic style of the dress is so majestic, she truly looks like a queen. As you can see in this picture, everything is green in this adaptation, that's the main color of the story here; she's even wearing it on her eyeshadow, which is really cool because it gives her a little bit of fairy vibes. Once again, there's a lot of glitter (even though a lot of it is cgi). This is one of the most regal ballgowns.
7. Libuše Šafránková in Three Wishes for Cinderella:
People usually think of the white dress at the end, but my favorite is the actual ball gown, the pink, white and blue one. It's a very pastel color palette. I love when adaptations try to integrate ways in which her stepfamily not recognizing her ties into her ballgown, in this case with the veil, which still matches the tiara and her hair. It's not an opulent dress, but it is still regal enough. It gives her an air of sophisticated simplicity. Also the necklace is gorgeous.
6. Lesley Ann Warren in Rodger's and Hammerstein's Cinderella:
Okay, so first of all, even though is not a version that's adapting the Grimm's version, it still has one of the ballgowns that are closest to how they describe one ballgown in the story: gold and silver integrated into the dress. Once again this is more of a queen's dress than a princess' dress, it evokes authority and elegance. Her crown and hairstyle are so admirable, she kind of feels like an ancient queen of Narnia.
5. Emilia Schüle's Aschenputtel:
All three of her ballgowns in this film are truly amazing, to the point each of them might be considered to have their own separate spot on this list, but that feels like cheating, so if I had to choose just one, it would be the second one. The silverish-blue color reminds me a lot of Disney's Cinderella, but there's a different unique element with each ballgown and this one has a cape. To my knowledge, no other Cinderella adaptation has her wearing a cape, and it really looks amazing here, as it is integrated in the dress itself. I also like that in all the ballgowns in this film, you actually get to see her face fully, since the rest of the film is hidden under a rag and ashes. It makes the contrast between the two moments of the story much more impactful.
4. Aylin Tezel's Aschenputtel:
Now, here's where some of my favorite film dresses (not just Cinderella dresses) ever start to show up. Aylin Tezel's ballgown is so dreamy, it feels like she is wearing a cloud almost. And yet, it's one of the most simple and humble ballgowns in a Cinderella movie ever; it fits her absolutely, as she is one of the most human Cinderella's depicted on film (in my opinion). My favorite part are the puffy disconnected sleeves. Once again, like Camila Cabello's case, her hair doesn't change that much. I love that it's just white with a slight hint of red pattern, to keep on with her color themes during the film. Also, to note Camila Cabello, Lily James and Aylin Tezel are the only Cinderellas to not wear any jewelry at all with the ball gown (including their hair).
3. Marcella Plunkett's Cinderella:
This concept for a ballgown is amazing, especially when contrasted to the other dresses at the ball in this movie. Her hair is stylized in a sort of wild and free way, it fits her so well. The ball gown itself looks like a mix of a fairy and a mermaid (much like this version's own fairy godmother character), with layers and cuts that look rebellious yet very elegant, it's very fashion but not in a vogue way, more like a pastel goth way. The necklace also fits so well, feeling like a separate extension of the dress itself. And this is one of the dresses very well complimented by the slippers, which in this case are purple rose petals ballet flats; once more they feel simple, humble and rebellious, all main traits of this Cinderella (which along with Aylin Tezel and Drew Barrymore are tied for the most human Cinderella depicted on screen, speaking of which...).
2. Drew Barrymore in Ever After:
So, the first two spots on this list will be very predictable, but that's not bad, since these first two spots are, in general, the best Cinderella on screen adaptations maybe ever (and I know I'm not the only one to hold that opinion). So Drew Barrymore's dress is one of the best dresses depicted on any film ever. People have analyzed the details of this dress endlessly because it has so much attention to detail. This Cinderella, which is one of the few to be set in the middle ages and not the renaissance, was looking to be very faithful historically with it's costumes takes. So the cut and embroidery is so regal, but the main part, of course, it's the wings. She literally looks like a golden angel, literally shining in every way. They also made a great choice with her hairstyle. It's very dreamlike and a true achievement of costume making.
1. Lily James' Cinderella:
How could it not be her? Many people (including me) argue this dress is even better than the Disney's 1950 original animated film. This dress is timeless, gorgeous and it truly looks made with magic. Like I mentioned before, she's not wearing any jewelry at all, many people don't even notice that and that's a true testament of how breathtaking this dress is. In the 1950's version, she doesn't appear in the crowd, the prince just goes to her and they disappear into the royal gardens. Here, before it happens, she gets the truly majestic entrance she deserves. Sandy Powell created the ultimate fairy tale princess dress. And it even has a theme, which most great costumes have. In this case, it is butterflies, which is another theme in general in the film. The dress is made of butterflies if you look at the transformation scene (as are the glass slippers). There's golden butterflies everywhere. And her hairstyle is so gorgeous and full of glitter. She doesn't even look like she's wearing too much makeup or anything. If I were to nitpick (and it truly is nitpicking, because this is the greatest movie dress of all time), I would say firstly, I wish they didn't enhance the color with CGI, if you've seen the dress pre VFX, it looks even better! The original more purple silverish color looks even better against the backgrounds and looks even more magical. My second nitpick is that, it was narratively supposed to be the same dress as her mother's pink dress (as she is "going with her" to the ball), but it looks so different in every way that it might as well be an entirely different dress narratively. But once again, they are nitpicks and don't take away at all from this wonder of dress making.