Well, I red all this thread so far (by the way, sorry for my english in advance) and nobody explained why sexy armor on girl (or women, no offense there) have the exact same protective value than their conterpart male armor? Simple! It's because the guys in the other army wont want to dammage her or will be too distract to hit correctly. For sure, it's not logic, but I thnik in a fantasy world this explanation could work . But, to be more serious, I think that the option of BOTH realistic and exotic (read sexy, and I mean sexy not porn) armor should be done like someone else already suggest. It's a game, so let's have some fun.
That's a funny case of when something that is intuitive and makes sense is horribly wrong. As anyone who's ever been in any sort of fight or high stress situation can tell you, if you're in that kind of situation and are distracted by unimportant details like that, you're dead. While that may seem like it proves your point, it doesn't. Pretty much any soldier worth their salt doesn't think about 'OOO BOOBS!' or 'Aw... she's cute! I don't hit women!'. They think "Mother f- is pointing a gun at me and my squad. It's a hostile target that needs to be taken out'.
And any woman who tries it in a fight is going to find that no one cares. When someone wants something and is willing to fight for it, they're not focused on your boobs.
Or to put it another way, when has being naked ever stopped someone who really wants to shoot someone else from doing so?
Now, this isn't to say that armor can't be sexy, feminine, and powerful, but as a handful of others have mentioned, this doesn't equal bikinis. A few pictures have been posted that are clearly feminine and attractive and overall aesthetically pleasing without being going into gag boobs territory. Female armor can denote and connote femininity without resorting to hackneyed ideas.