"Closet favorites" refers to items or clothes that someone loves and enjoys wearing, but instead of openly showing or expressing their liking for them, these favorites are kept hidden or kept to oneself, like in a closet. Full definition
I decided to go ahead and rock this spring - leaning look — one that includes three of my current closet favorites all together. (seasons-and-salt.com)
Two of my constant closet favorites are stripes and gray. (adashofpretty.com)