hmmm, i'd say... haruka, an, ichika, and mafuyu. also, from a biased point of view, akito
(+ the aforementioned shizuku, just mentioning her again)

• haruka's design is just very beautiful. her default hairstyle is really nice, and i think she gets the best alt hairstyles in the game, with the "worst" one being her most recent one, but it's far from bad. she's really pretty...!

• an is also very pretty. i believe she consistently gets the best cards in the game (bridal an is among my top 3 cards in the game), and all of her hairstyles are also great. i also really like her BNW outfit, it's so good... she's a really cool and pretty girl. epic design, really

• ichika looks nice. by now you'll see most of my comments are "they're pretty" and. Yeah. she's pretty. her default design has a really nice charm to it. she's pretty cool. also her default outfits are both really nice. furthermore, her alt hairstyles are mostly nice. god i love her FES and DLF and knight hairstyles... augh

• mafuyu also has a really gorgeous base design. idk how to explain it but i just enjoy it a lot? that air of mysteriousness... if that makes any fucking sense. dark and mysterious pretty???? idk. very beautiful. admittedly half of her alt hairstyles are kind of just fine, with her best ones being darkfes and wonderhorror (twintails nurse)

• honorary mention is ena. i love her old default outfit, it's so nice. and her default design and hairstyle are really nice. i kind of like short-haired girls, they're very charming. i can also mention shiho as an honorary mention; very cool and pleasant design haha

• now, from a biased point of view... akito has a great design. i could go on a whole ramble about his design but i dont wanna seem biased (lol), but he has been designed so well and really appeals to me. he's cool and handsome, but also cute and lame (although this is moreso about his design rather than his character). he gets great cards (most of the time) and lims and alt hairstyles (although they could be much more creative with him, tbh). and his BNW outfit is extremely good by the way, great redesign. i love his gay tmasc swag

sorry if the answer's kind of lame, it's hard to explain why i like stuff LOL