Let's start off with some of my favorites from this category.
~ Uresai Yatusra: You know, the one with Lum. It also has the Tengu-babe Kurama, Shinobu(Ataru's original girlfriend, and the girl with super-strength for no apparent reason), the stellar biker-chick Benten, the smoking hot ice princess Oyuki, Sugary sweet Ran, the Spice girls(Sorta like a female gang of idiots, Sugar the disappearing yukionna, Ginger the catgirl who plays possum, and Pepper, who can shed her skin), the priestess with the flawless metabolism Sakura, the spoiled little rich girl Ryoko, the sheltered rich girl Asuka, Lum's uncomprehendable mother Mrs.Invader(for lack of a better name), and knowing this series I'm probably missing a few of them...
~ Ranma 1/2: The grandaddy of gender-bender comedy, and another one with a long list of characters...
Female Ranma(also known as Ranco), Akane, Nabiki, Kasumi, Shampoo, Kodachi(also known as the crazy girl that almost no one cares about), Ukyo, Hinako(the mixture of lolita and bombshell, she switches between the two frequently), Mariko(Forgettable cheerleader girl), Akari(the cannon girlfriend of Ryoga, she trains sumo pigs), Azusa(the immature ice skater, who takes cute things for no reason), and as with Uresai Yatsura, I've probably glanced over a character or two.
~ Samurai Pizza Cats: Finally one that has a short list of characters... Also, since I, and probably anyone who remembers this series, has only seen the American version(I have been looking for the subbed Japanese version, but no luck), so let's use the American names, `kay?
Polly Esther the pink cat girl with an attitude, Francine the owner of the pizza joint and cat girl version of Nabiki(sorta), Lucille the shy girl with missiles in her hair and shoulders, Princess Vi the spoiled little bunny girl, Carla the crow girl(never watched the episodes with her, but I'm using the wiki, so I'll put her in), Deedee the American dominatrix cat girl, and Princess Vi's mother, who's name escapes me.
~ Ghost sweeper Mikami: One of the hottest misers you will ever see, another series with a long list of characters.
Reiko Mikami(the star herself), Okinu(the resident ghost, later on ghost sweeper student), Maria(the android girl made in ancient times), Teresa(the modern android girl), Emi(the rival ghost sweeper with dark skin, deals mostly in voodoo), Meiko(the sweet innocent girl, who controls 12 shikigami, also hinted as being a lesbian, especially for Mikami), Michie Mikami(Mikami's mother, she's still quite young, and can travel through time using lightning), Yuriko Yokoshima(the perverted apprentice's mother, a strict business woman), Hinome Mikami(Mikami's younger sister, still a baby, but we can do the old standby of time-skipping, she is also a psychokinetic, with a tendency for starting fires), Mari Ichimonji(the ex-delinquient girl friend of Okinu's), Kaori Yumi(a strict school girl from a long line of exorcists), Megumi Marin(a restaurant owner and a witch, makes magical food for her customers to fix supernatural problems), Tamamo(a nine-tailed fox girl, loves Kitsune Udon, and has been adopted by Mikami), Shiro Inuzuka(A wolf girl who acts more like a puppy, competitive with Tamamo), Shoryuki(the little Dragon Princess, spends most of her time up on top of a sacred mountain), Hyakume(the all-seeing girl, has a hundred eyes, and claims that nothing escapes her sight), Medusa(A bad-girl Dragon god, looks and acts like a dominatrix most of the time), Mephisto Pheles(Mikami Reiko's past-life, a low-class demon who fell in love with Yokoshima's past self), Luciola(A firefly-turned-demon-babe, controls light and illusions, yet another girl to fall of Yokoshima), Vespa(A wasp-turned-demon-babe, uses mostly her brute force and speed than magic, was in love with the big-bad Ashtaroth), Papilio(A butterfly-turned-demon-loli, treats Yokoshima like a pet dog), Aiko(A demon possessing a desk in Yokoshima's school, she's only interested in getting to know school life), and Kobato Hanato(a poor girl, who's been suffering with the god of poverty her whole life, until that was fixed by Yokoshima and Mikami's intervention, turning the god of poverty into a god of good luck, the only normal girl to fall for Yokoshima).
~ Other series: Need I say more?