The most attractive/hottest female character in Code Geass is in fact Milly Ashford!
She has the best female design and appearance. Milly is described by other characters as being incredibly attractive. She has shoulder-length blonde hair, fair skin, blue eyes and a curvy figure. During the second season, her hair is occasionally wrapped in a ponytail, as seen at Odysseus and Tianzi's wedding reception. Following her graduation, she cut her hair shorter to where it was about the length of her chin. For most of the series, she is seen wearing the Ashford school uniform, but upon becoming a reporter she is mostly seen wearing a turquoise vest and white dress.
Her design is better the most of the other female characters, she doesn’t have ridiculous colored hair or a unatural body figure. Her character design is more realistic.
In one of the Code Geass magazines, Milly is ranked number one in breast size, of all the female characters in Season One. Just another example why she’s hotties girl in the series.
She’s very interesting character her beauty and personality is awesome. In the beginning of the series it appears that Milly is somewhat of an antihero with a bullying demeanor. She will often toy around with people's insecurities, being fully aware of most around her due to force as the President, leading some, such as Shirley and Nina, to view her as condescending. She will occasionally go as far as to rally the entire school into finding out others' secrets, and will often go over-the-top with events, to the dismay of some and the excitement of the rest. In reality, Milly is merely trying to be playful, and other people such as Lelouch often see this due to her boisterous personality. She deeply cares about the people around her and remains serious when the matter calls for it, often becoming internally upset when people reject her kindness. She also displays some form of resistance against the people around her, rejecting Lloyd's interest (or lack thereof) in her and her noble status to remain happy in life.
Milly is Lelouch's friend and classmate at Ashford Academy. She also has crush on Lelouch. She has a curious and playful personality; for example, she often gently teases her friends about random things; such as Shirley's inability to express her true feelings for Lelouch openly. Milly is generally good friend a good person she was willing to gave up pursuit in development and cashing an romantic relationship with Lelouch or even expression her true feelings for him due to fact that she didn’t want to hurt Shirley’s feelings. Because they both loved Lelouch.
Throughout the series she is spotted to have some desire to be with Lelouch from time to time. Despite all this, she can sometimes be quite caring, as shown in Episode 9 (Refrain), when she discusses with Kallen about her parents. She is eager to discover Lelouch's secrets; often using over-the-top methods in attempting to find them - so much as to rally the entire school into chasing after Arthur when she suspects that the cat is holding something precious to him.
Milly cares deeply about Lelouch, but realizes the need to restore her family's status by marrying a noble. She is aware of Lelouch's identity as a former prince of Britannia, since her family were close supporters of his mother, Empress Marianne. This relationship however, would lead to the family's nobility status being stripped.
The Ashfords, wanting to restore their former glory, have two options in doing so; either reinstate Lelouch and Nunnally back into the royal family, or to arrange a marriage with a noble. Since the former would get both of them killed, the Ashfords opted for the latter, and arrange several marriage interviews for Milly, with Earl Lloyd Asplund.
Milly Ashfords is the hottest female character and she would’ve been the best possible lover for the main protagonists Lelouch in general. She loved Lelouch but she wasn’t obsess or madly love with him. She was just in love with him from knowing Lelouch for very long time. Milly is a normal girl she’s not a terrace lunatic, a witch or crazy love sick girl. She was playful girl with a positive personality. She would of been the ideal girlfriend/Wife for Lelouch. Especially if Lelouch never lost his title as prince. It just shows you how much of a poor hand Lelouch had in life.