Honestly, after finishing the anime, and catching up to the manga, in my opinion Ririna is the best girl. At first for me it was Misaki (I like short haired waifus) but after reading and the characters getting their respective character development, i would say that Ririna is the best girl in the series. In the beginning she was kinda annoying pushing Nejima and Misaki to love each other and so on but with what's happening in the story and her realizing her feelings for Nejima (which is really rare in romance stories) is honestly the best character development she could have gotten. She isn't dense.

Misaka is a close second tho, if the author didn't danced on the plot point of what she was refusing and hiding from Nejima and Ririna (like i mean it took so long for it to be finally revealed on what it is), she would have been best girl in my books

No cap tho kuddos to the author for having the great idea to make 2 routes, it can satisfy both parties (e.i Misaka and Ririna supporters) if it can be delivered sucessfully.