Beside completely naked, which state of dress/undress do you like when a girl is exposing herself?
Alternatively, which article of clothes do you prefer to be the last piece for a girl to take off?

For me:

Wearing only panties - A girl is almost naked but their most embarrassing part is still hidden. And they try to keep panties on as long as possible to protect their last dignity. I find character expression in this state pretty cute.

Naked with only Ribbon+socks+shoes (sometime also have panties) - It feels like character intentionally not wearing some clothes on rather than they're in the middle of dressing/undress. It is clear that to other observer that something is wrong.

Bottomless (with or without panties) - Characters seemingly dress normally until you look down. Strike Witches introduce me to this.

Wearing only bra - I like it for how rare it is. Most of time, characters will choose to off their take bra off before panties. Moreover, characters who keep bra as the last piece usually have some kind of complex about their boobs.