Bookshelves are usually about as bad a home for speakers as you can find due to proximity to the wall (among other reasons).
Other than some on-wall designs (which should be ok), there are a few speakers which were designed for bookshelf use.
The old Linn Kann, Wilson Duette, and NHT -can't recall the model name- are specifically designed for close to wall placement.
Some studio monitors (I'm thinking Lipinski) will offer a mixed bag - plus in bass reinforcement, minus in imaging - and might be good options
However, If you like dramatic imaging, stick to stands.
Marty