Indie clothing designer Skin.Graft has copious amounts of fancy (and Goth) as one of its hooks. Just check out their wedding gowns.
Just about any coronation dress by default, men and women.
In Britain, even the peers and peeresses are required to wear ermine trimmed robes and dresses for the coronation. One of the more notable of these is worn◊ by Consuelo Vanderbilt◊. Notable due to her being part of that famous Gilded Age family.
Also, courts such as Versailles, and the British court until recently, practically required such dresses.
Speaking of the Gilded Age, this trope probably accounted for a third of the reason it's called that.
Marie Antoinette usually followed this trope, since her position required she wear the best dresses, but she once caused an uproar for wearing a dress in a painting that was actually simple◊. It's essentially like seeing the Queen Elizabeth II wearing only her underwear for a royal photo.
This comparison is made more serious when you know that muslin really was used for underwear. Another problem is muslin was an extremely cheap fabric, and French Royals of this period were definitely known for conspicuous consumption.
The previous queen, Marie Leszczynska (Louis XV's wife) also had several dresses that can be seen in her portraits. One is a this◊ bejeweledermine dress and cape with Fleur de Lis, that likely inspired Antoinette's similar dresses in Rose of Versailles. But that's just one of many dresses she wore for portraits. One of her simpler ones was a blue dress with lace trimmings and a lace stomacher, and an ermine petticoat. Her most common dress decorations were fur, lace, embroidery, and brocade.
Her older sister, Mary, wore some very fancy dresses as well, particularly a black velvet dress◊ with puff sleeves, frilled collar and cuffs, Gem-Encrusted belt, decorated underdress, and the overdress is trimmed with white ermine.
The Pope's vestments throughout history are often this, as are some Cardinal robes.
Dresses in competitive ballroom dance are almost always this.
For a few centuries, it used to be the fashion for boys up to around five to wear dresses like their sisters, and some could still be quite elaborate. Take this portrait◊ of a prince of France in the mid 18th century, wearing a blue dress trimmed with black sable fur (and matching hat with blue feathers). It's like a miniature version of a dress worn by his mother◊ and then his sister.
Diane Kruger has worn a number of dresses by Karl Lagerfeld.
Tsarist Russia actually had a Dress Code to help make their dresses distinct from the rest of Europe's aristocracy. This included the distinctive hanging sleeves, an overskirt with a long train, and the Russian-style tiara.
Eve Torres, at awards ceremonies, and once won a match in an evening dress.
Most "red-carpet" events, but especially the Academy Awards. Halle Berry's 2002 dress (featuring a velve skirt and elaborately embroidered flower pattern on the bodice) is a prime example. Several times a year, "Best Dressed" (and often, Worst Dressed) lists appear, with galleries of pimped-out dresses.