[Slippery_John]

I prefer the windows at the narrow end. Gives me more useable wall space. In fact my current apartment is much like your image (though with a bedroom on the side) and my previous was more like one with windows on the long side.

I've got a lot of books and board games that I keep in shelves, and so the much increased wall space allows me to place them more comfortably. I'm not interfering with light sources and I can secure the shelves to the wall so they don't fall down if my dog runs into them. It also makes it easier to keep the place cool in the summer since there's far less surface area to worry about.