Lily is my favorite character design from this series, not in terms of attractiveness. Overall design.
Comprehensively, she's really well-rounded in terms of character design carrying through her character, or vice versa. Her design comes off young (which she is), a little overly immodest in her clothing choices (she is actually the least-dressed character, which connects to her former profession that she shared with Klein), but also perky and a bit of a tomboy (carrying through her love of gunpla kits), and mischievous (since she was Eve's handler and arranged all the matches and gigs). Her design is simple, and hits all those points. The story filled in all the aspects as we went.
But Eve is a close second. Third was Anri (Rose's punk street hustler).
Aoi is generic ojousama. The rest of the cast is meh, but they all have great voice actors.
I do like Eve's outfit in the ED best out of all the golfing outfits. Same with what Rose and Anri set her up with for that single day event. If we're going for attractiveness, Eve's VR catgirl all the way. It suits her, and the VR clerk in Nafrece knew it after talking to Eve for a couple seconds.