I like Holly a lot better. Minerva just comes off as this spoiled little girl who thinks everything should go her way because she's a genius.
I, personally, don't think Artemis should be with either of them, but if I had to chose I'd say Holly. She knows him and she knows how to handle him. They've been through a lot together and she's one of the very few people he trusts (and vise versa).
