For me it's
1. Harper - Also I just always thought she was cute when the MC comforts her + she is one of the few LI that it just feels like the MC is slowly getting close to instead of every girl wanting to be with the MC with no built up relationship. so to me how Harper builds a relationship with the MC feels more natural compared to most of the girls here and she could pass as a non harem LI in any game. even more so after we see her naked now I think she has the hottest body out of all the LI but she was my favorite before that.
2 Shauna - If there was a single LI the MC should be with I feel she should be the one since she has known the MC for so long and had feeling for him for a long time and maybe the MC too. Not gonna lie her Blowjob fetish makes her look cute as hell sometimes.
3. Stacy - Her backstory
+ just being a hot redhead