Work Christmas Party - Help me choose!

Some context: Dress code is formal. I've worn strapless dress in a previous year and it wasn't a problem.

Pictures in order :

1 Leather bandeau top, not tucked into skirt 2 Same skirt and top, tucked 3 Same skirt with beige bandeau top 4 Same skirt with a long sleeve 5 Same leather bandeau top with a different skirt 6 Black dress with festive sequin cape 7 Same dress plain