The thing is, Vaan dresses better than Fran but no one ever complains about the latter because, well bunny girl and fan service. I think Vaan dresses appropriately if you look at other Rabanastrians.
Anyway, I'd like to talk a bout a few series that I like.
Metal Gear Solid:
I love both The Boss from MGS3 and Meryl in MGS4. They're both dressed appropriately, come off as strong women without losing their feminine touch. Sniper Wolf in MGS1 is also great.
On the other side of the spectrum you have the trash tier design of Quiet in MGSV. The in-game excuse for her outfit is just laughable. I think they handled the whole fan service bit far better with EVA in MGS3.
As for the male characters, most of them wear what you'd expect them to wear. It's very by the book, but it works.
Resident Evil
Ada Wong in RE4! Not practical, but it totally suits her character. Leon also looks great in that game. Perhaps the only time he's ever been desirable both aesthetically and in terms of personality.
Chris looked great in RE5 and while her blonde incarnation didn't impress, Jill's costume from Lost in Nightmares is a very nice take on her original, iconic one from back in the day.
Tekken
Leo, Lili, Kazumi and Master Raven are all on point. The Mishima clan usually look good too, either wearing suits and or karate pants. Of course, there's a lot of badly dressed fighters too, like Lucky Chloe, Katarina and Alisa.
Will probably make another post at a later date about other series.