I like the classy and traditional look of six, but after reading some of the posts, I guess number four seems to fit better, although it's outdoors, when it should be indoors.
On the other hand, if we are going to be using the others as candidates for Kyon's and Haruhi's bathrooms, I think the first one should be Kyon's, since there's that bunny-shaped sponge that I can totally imagine belonging to Nonoko, and that the second would be a good choice for Haruhi's, since the others look way too big and/or elaborate to belong to a middle-class home.