Kuroyukihime's web avatar in Accel World wears a short dress with a butterfly motif around the waist, and feather-like trim on the ends of her Opera Gloves and the neckline of her bustier.
During the expo in Afterschool Charisma, the clone of Elizabeth I wears a dress like the original Elizabeth wore, with a ruffled overskirt and underskirt, puff sleeves, a double layer pearl necklace, bejeweled neckline, a high lace-lined collar, and a gold bejeweled tiara.
Shalott's dress in Air Gear has a frilled apron, a overskirt cut like a ring of ribbons and with intricate embroidery on the hem, and a frilly petticoat. By the way, that's a guy.
The manga Alice Quartett, about four clothing designers who run a boutique together, has them collaborate on a Pimped Out Dress in the first chapter.
The royal family and court of Midland in Berserk. Princess Charlott'es first dress we see has a pink overdress, a white frilled underdress, and two rows of white fur puff balls from the top of the bodice to the hem of the overskirt.
Casca even wore one with lots of frills, including a low frilled neckline, when the Band of the Hawk was still in good graces with the king.
Baccano!! Chane received one from Claire. It included custom-made holsters for her knife.
At least in the anime adaptation of Bodacious Space Pirates, Princess Gruier Serenity wears a white dress◊ with white flowers trimming it, gold trimming on the bodice, a skirt with lots of ribbons and overskirt layers, and gloves with three layers of frills at the end.
In The Cat Returns, while Haru is at the court of the Cat King, she wears an Elizabethan-era style gown, with hanging sleeves, a gauze heart-shaped collar held with wiring, and a huge neck ruff.
Le Chevalier Deon had a Limited Wardrobe, but those dresses were still grand, frills, trimmings and all, and many of the historical characters wear dresses directly see in their actual portraits.
About every time Chi would see her "sister" in Chobits, one or both of them would be in a filly, flouncy dress. More showed up in the bonus art.
Layla wears a pink dress trimmed with white ruffles, a white ribbon wrapped right below the waist, a dark pink petticoat, and a headband trimmed with ruffles.
Michelle's dress is a short light pink dress over a darker pink underskirt, both heavily trimmed with frills, puff sleeves, and a frilled bonnet.
In both the movie and anime of Fatal Fury, Canon Foreigner Lilly wears fancy dresses. In the movie, she wore a pink dress with a fluffy feather collar. In the anime, she wore a dress with a white top and a brown skirt, frills on the hem and neckline, puff sleeves, and a green bustier over the dress.
The "Sorta Cinderella" dress in Fruits Basket has puffs, frills, and lace.
The dresses for the protagonist princesses in Fushigiboshi No Futagohime each has a frilled cuff, a high frilled collar, a frilled petticoat, a large ribbon on the bodices with a jewel in the middle, and gold trimming including trimming on the skirt in the shapes of hearts.
Glass Fleet has some truly weird dresses. One dress is made to look like it's inside a seashell. Not by embroidery or cutting the fabric a certain way, there is an actual large seashell that takes up most of the skirt. Another dress has a huge snakelike design wrapping around it, from the head to the skirt.
Princess Fala/Allura of Go Lion/Voltron, has a fancy pink dress that is similar to Aurora's dress in Sleeping Beauty, but has a lot more white trimming on the sleeves and skirt (in addition to the distinctive neckline), a lighter pink underskirt and stomacher, and a white petticoat.
Princess Amue/Romelle wears a blue dress that isn't that fancy aside from the pink frills, but her pink Minidress of Power is more pimped out, with some red jewels, and a short white cape.
Josephine in "Bluebeard" is offered lots of dresses, including a white one with several layers of ruffling on the skirt, and a pink on with several ribbons and ruffles.
The dress made for "Cinderella" is pale pink with plenty of frills and ruffles, and a yellow flounced petticoat. Even the queen wears an orange dress with golden trimming, white ruffles and petticoat, and giant poofy sleeves. The stepmother and stepsisters have their own fancy dresses as well.
Leonora in "The Frog Prince" wears a pink and white dress, complete with poofy sleeves and fur-trimmed neckline.
The princess in "The Water of Life" wears a yellow dress with a pink petticoat of several layers of frills, and a fur-trimmed neckline.
The princesses in "The Worn-Out Dancing Shoes" wear several dresses, with the eldest wearing a Fairytale Wedding Dress at the end.
Lunlun's magical dress in Hana no Ko Lunlun starts out simple, save for the huge frilled sleeves (which only avert giant poofy sleeves due to not being actual puffs). Yet Frilly Upgrades give her even more elaborate dress with more flounces and frills, layers and tiers, overskirts and pettycoats, and some actual Giant Poofy Sleeves. Just check out the image links page.
In the film of Howl's Moving Castle, there isn't much that's really elaborate, despite the opulence of the era and the film in general, but Madame Suliman shows off her dress with the gold trimmings, jewelry, and fur collar.
Camille's most common dress is a light blue one with black trimming, asymmetrical overskirt with ruffled edging, striped underskirt, and medium poofy sleeves.
Alice's most common dress is pink with white frills, trimming with dark pink ribbons and bows, overskirt that is like an apron on the front and back, and oversleeves that are two layers of flared fabric.
In Interstella 5555, Stella wears one to attend the "Gold Record Awards", that has a skirt that is cut to show off her legs in the front (but enough on the front to avert Showgirl Skirt), and has so much fabric it bunches up in frills.
Most of the costumes in Kaleido Star are loaded with fancy trimmings.
Kilala's princess dress in Kilala Princess has a long skirt that is open to show several layers of short flounced petticoats, has puff sleeves, ruffles trimming the neckline and down the front of the bodice, a flower and bow worn like a brooch, and a Giant Waist Ribbon.
Katherine McDonald of Kaze no Stigma wears a red dress with a white skirt, frilly trimmings on the sleeves and bodice, and the top cut like a jacket, with the collar open to show a generous amount of cleavage.
Mahou Sensei Negima! has Ayaka, who can often be seen wearing absurdly elaborate outfits on normal days. There's also Tsukuyomi, who wears such outfits to sword fights where they'll undoubtedly be torn to shreds. The next time she appears on-screen, she'll invariably have a new one to destroy.
The nature of the "Princess" program in Princess Princess requires wearing fancy dresses, most loaded with frills and lace. This is subject to whoever's in charge of the sewing club: the program during Arisada's time skewed more toward Kimono Fanservice.
Puella Magi Madoka Magica has its titular character dressed this way to the point where she's deemed the most elegant magical girl in all of them. Expect lots of frills, petticoats, ribbons, and puffs.
In Ranma ½, Ranma is forced to wear several in the "martial arts dining arc".
Marie Antoinette of course got the most dresses, with a standout dress being one that is not only trimmed with ermine, but the ermine itself is decorated with diamonds (it's the same with the ermine on her cape). And at least in the manga, she wore a nearly identical dress for her husband's coronation (the difference were a frilled neckline, different hairstyle, and a jeweled headress instead of a little frilled hat). They double as a near Whole Costume Reference to a Real Life one worn by Marie Leszczynska, the previous queen of France.
Madam Du Barry had quite a few herself, showing her favor from the king.
Rosalie also got several. One had an overskirt with frilled trimming, and long hanging sleeves.
And Lady Oscar even wore on to go on a date with Fersen, with small puffed sleeves, a skirt that wrapped half again around the waist, and edged with embroidered trim.
So does Zero no Tsukaima. Could this be a common thing with J.C. Staff? Take Janettes dress and Henriettas dress in particular.
Shattered Angels has some very fancy and elaborate dresses, even for servants. School uniforms looks very elegant, especially for the boys, and the student council. Then there are the dresses worn by Absolute Angels.
In Slayers, Princesses Amelia and Princess Martina normally wear a practical and slutty outfit respectively, but they do wear grand dresses a few times, Amelia in pink dresses, and Martina in her wedding dress.
Both sets of battle dresses in Wedding Peach. The first stages are fancy wedding dresses, and the second stages are mini dresses with frills, gold trimming, and feather trimming after they got a Frilly Upgrade. Peach's first stage dress is very similar to her mother's wedding dress, although the Giant Poofy Sleeves were trimmed with gold on her mother's dress, while Peach's are trimmed with ruffles.