Please recommend a top-notch bookshlef speaker

My favorite is the ProAc One SC. A fantastic stand mounted monitor. Dynamic, fast and disappear as good as the best will.

what are you driving the speakers with?

I am using a Denon 2808ci receiver, and blue jeans cables.
I intend to place them in a built-in cabinet. I may have to enlarge the pre-existing speaker grills to fit a more modern [air of speakers. There are three of them, and it is a large open floor plan at least 1500 sq. ft. Opens to several rooms, including the kitchen, DR, LR and sunroom.

A speaker that rarely gets much mention, but offers excellent performance, is the Sequerra MET 7.7. The speaker is designed and made by Richard Sequerra, probably best known for this high-end tuner some years ago. The speaker is now offered in both a standard model and a self-amplified model. I owned a pair of MET 7's for a number of years and sold them quite reluctantly. Here is the link to Sequerra's web site:
http://www.sequerra.com/electronics/data/index.htm

I am surprise nobody mentioned the LS3/5A or the LS3/5A V2. The former is no longer in production but you can get the V2 from Stirling Broadcast. Add a sub like the AB1 and you are in audio nirvana.