It's so hard to choose when there's so many great options!
I have a crippling weakness for scalies so sewer frog gets massive points for me since she's the most scalie enemy we have currently.
I also really like scp 1471. It may be a bit greedy & out of scope, but i'd love to have more scenes and content with her. Ideally I'd want to be able to get completely on board with the mc treating her like his wife and really live out that fantasy by breeding her, pampering her and spending more time with her in general.
Maybe even find a way to make her fully corporeal and have her serve as more of a house wife? Cooking meals and relieving "stress".