Leaning ladder shelves are a trend that is pretty well on its way out, and was never a very good look. I'd opt for bookcases on each side; it will not matter if they're not symmetrical. I'd make certain to fill them primarily with books, not just as staging shelves for knicknacks, for this to look right.

Do you have enough room for either one of these bookcases from CB2?

Looks like there's a door, light switch and outlet on the left side. Try a small table there with a lamp on it. It can serve as a night light for the room Add a tall plant in a pretty cache-pot on the right.

Embrace the asymmetry. Symmetry forced will annoy you, well...it would annoy me. Deco enthusiast has some great ideas!

Thank you all - while bookcases would be easy and quick, I only read on my Kindle, so I they wouldn't be as functional in my case. So, I am going to roll with the asymmetry.-decoenthusiaste's plan. I think a tall plant on the narrow side will work. On with life!

Any pets? Seems like a great spot for a fish tank or bird cage or even a crazy cat hangout area with shelves and what not. If ya have pets it would at least make the space useful.