Gambler wrote...
If they aren't wearing sailor fuku, then they cannot be considered as 100% schoolgirls. :D
I am with you, but in addition to this, the examples provided don't fully grasp that severity of this question *or I may be taking this topic itself, too seriously* but moar example are need to be showed before an exact answer should be given, the only example given thus far really is just a bunch of the Ikkitousen girls,(and Haruhi) which by standards really isn't all about the school unifroms (don't argue with me about this plz, I am not trying to devalue the series or anything particualr, just saying...) I wouldn't mind providing some example myself but, they'd tend to be full of sweet innocent lolis, and by default should be in "sailor fuku" attire, now once the subject has developed clothing can be changed and add different appeal toward different ppl, thus it can be hard to decide upon which uniform is preferable.
I don't have time to look for the non-loli pics so here are some quick pics, on each type of "fuku"
Quick "Sailor Fuku" examples
Vest/Jacket examples
One-piece suit examples