tablejockey: I completely agree that the visual aesthetics of one's listening room are important (unless you listen in total darkness). Still, jssmith has a point: many of the pictured rooms look acoustically dubious. Acoustic concerns have to come first.
My listening room has a huge picture window with a view of mountains, valley, and a stream below—but that view is BEHIND me when I'm listening. Jim Smith suggests that's as it should be; that light streaming in creates a psychoacoustic effect of "glare" (tip #46) if you're looking directly at it. Still, if I could look at my view when listening, I would. It's just that it would be too difficult to set the system up that way.
dekay: great photo! But where's the sweet spot?! Can you tell me (maybe in a DM) how to insert a photo here, without it's being in a URL? I know this question has been asked before, but I don't remember the answer.