Bookshelf speakers that sound good on a SHELF or SIDEBOARD

Not a 100% written in speaker design laws.
But mounting on a shelf or sideboard, usually means your going to get some bass loading addition because of close proximity to walls, corners or the sideboard itself.
Because of this I would look more to speakers that are infinite baffle design (sealed enclosure)  not ported, as these will help keep the added bass bloom down.

Cheers George    

The Wilson Audio Duette was designed for bookshelf and stand. These are the BEST sounding bookshelf speakers I have heard period. But they are very pricey.

Any LS3/5a type sealed two way should work fine. Harbeth, Spendor, Falcon, etc, etc.

Regardless of what speaker you get, if you're not going to put them on dedicated stands, try the IsoAcoustic stands. It's the next best thing.