I posted your pictures in the body of the message for easier comparison.

I prefer #3 because the vanity is a bit longer than it is in #1 and #5. Also, with the closet enclosed, you have more place for hooks, etc. on the interior walls.
What kind of doors do you plan to put on your closets? I prefer to close off the closet so that moisture from the shower won't get into the clothes. There seems to be more potential for that in #4 unless you are careful to always keep the closet doors closed.

Are you planning new or doing a remodel?
I would love to enclose our toilet in a separate space; but we cannot easily move plumbing in our remodel, so we are stuck with the shower and toilet in the same small room.