A book shelf speaker to go on a bookshelf.

If you can find a less expensive, used version of the classic LS3/5A from Spendor (or another British manufacturer with the BBC license to produce this model) you'll be pleasantly surprised at the high level of listening enjoyment.
Mine are positioned at the front of the bookshelf edge, and you can experiment with support, such as AudioPoints, or Aurios, or Mi-Roller. Great for nearfield listening since the sound image snaps into focus amazingly close to the front of the speakers, and does not have deeper bass, so not as wonderful listening far out in my room.

Some Linn's. Thiel SCS's.

I've tried a lot of bookshelf speakers, my preference is Totem Rokk monitors. No longer in production, you should be able to find a pair for less than $400 on the used market.

Allison has a wonderful speaker designed expressly to sit on a shelf. Has excellent bass response. It is not inexpensive; think it is around 2500/pr.

Linn Tukans do well on a shelf, too, and placed near a rear wall as they were designed with this in mind. The Tukan is one of the better true bookshelf sized moniters out there and s/b about 500/pr used.

A recent copy of the Absolute Sound had an article featuring a speaker which was engineered to go on a bookshelf. I think the article was earlier this year or late last year and I think they were North Creek Audio speakers.

Might be worth tracking down the issue.
http://northacoustics.com/

http://www.theabsolutesound.com/newsletter/150/startmeup.html

Reasonable price for the speakers under a grand, new.

this is the TAS article.
Richard Bischoff