So gorgeous! You are so lucky to own that collection - especially since if I were you I would never be able to pick a favourite. Pears, rubies, rose gold, yellow gold, oh my!
There are so, so, so few halos I genuinely say

too as they are just not "my thing", but I always always do when I see yours! I just think the antiquey milgrained look (and the "chunkier" style if that makes sense as they are not chunky but they are not delicate either!) in the yellow or rose just makes them look so classic and elegant. Like the royalty of the halo world!