Hmm...
FE 1/3/11/12: Maria (I also really like Minerva, Est and Catria)
FE 2/15: I have problems to choice one character here... My option would be Faye, Silque, Mathilda, Mae, Genny and Sonya xD
FE4 Gen 1: Tailtu is a cool girl
FE4 Gen 2: Julia
FE5: Sara
FE6: Sophia
FE7: Nino
FE8: I guess is Lute or Amelia
FE9: I don't have a particular favorite here... Eh... (Maybe Mia?)
FE10: Micaiah!
FE13: Well well... My choices change over time here... Sometimes is Tharja, sometimes is Olivia, sometimes is Maribelle... I'm not even sure xD
FE14 Birthright: Sakura
I still need to play Conquest... some day..