I'm in the same boat as you. I've had large speakers (Infinity, B&W, Polk) and decided to go the bookshelf route. I just purchased
Infinity RS2000.3 and
Pioneer SP-BS41-LR. Bought the BS41 after reading
Stereophile review (where it was compared against Paradigm Atom v.5 and Wharfedale Diamond 10.1).
The BS41 is very impressive and produces more bass than I've ever heard in a small speaker and it's quality bass. Speaker is also very balanced, maybe just a tad bright at times. RS2000.3 is not too shabby, lacking just a smidgeon of detail (in area of cymbals, mids) that decent larger speakers can have. Either of these speakers have no trouble filling up a room.
Check out the Stereophile Bookshelf reviews! They are very good.
Pioneer SP-BS41-LR loudspeaker | Stereophile.com