Bookshelf speakers with the best bass...

I'll second Red Rose. Sugerbrie's advice should also be headed. The Red Rose monitors are ported in the rear, and if they are not set up right they will sound pretty bad. If you are forced to put these into a bookshelf--these probably won't work.

Look into the Dynaudio 1.3SE. They retail for about $3500. You could probably get them for your price.

Ditto on the Dynaudio 1.3SE. They are an amazing sounding speaker (on stands).

Agree with position and stands as issues. Direction of port can also be an issue with bass and room placement. The Tyler Taylo reference has a front port which makes it easier to place near walls.

I own both the red rose and the ref 3a. Both have extended bass response for their size, but little else in common. The red rose is much smaller. It is also much more "forward" in character and requires much more amplifier to function properly. (I use the ref 3a with 11 watt set amps, the red rose speakers require a push-pull or ss amp.) So, depending on your taste (forward vs polite) and amp/room size, you will likely find one of these speakers a much better choice than the other.