The classics can't die, no matter what
TakAcchan : The sweetest, inspiring, absolute BFF
SaeYaka : kickass + kickass = beyond infinity
No matter how many girls fell for Sae, she herself will always fell for Sayaka (and vice-versa)
KojiYuu : The perv never ends!
Bonus...
ChikaReinyan : Not as popular as above, but you can't help to not go d'aaaawwwwww...
AkiTarie : The hilarious W weirdo