The best "imaging" speakers?

For full range, multiple drivers configured to approximate a point or short line source might image almost as well as a single driver can because the geometry of how the sound propagates is similar.

There are some omni designs that do this trick with inherently wider dispersion in 3-d. Morrisons, Wolcotts, and OHM Walshes are good examples.

Small monitors and some floorstanding Totems like the Arros are other examples in a more conventional box design.

I like these designs for good imaging best, especially for more nearfield listening. For listening from a distance in some larger rooms, taller line source or floorstander designs with multiple drivers can work better as well.

I'll offer Beveridge speakers!

What about the humble Eidolon?

Audio Physic spark ver 4 produced a great image with a deep soundstage in my humble system. The only caveat is they need to be rather far out from the rear walls

The mbl 111s were the best I've heard.

101s are probably as good or better and more dynamic from what I know but have never heard them.

Magico minis were also very good in a smaller room and so were PSB Synchrony series.

OHM Walshes are also very good. mbls had deeper soundstage but not wider. OHM Walsh omni sound levels are physically damped in wall facing directions, which may inhibit soundstage depth but enables them to go closer to walls and fit into rooms easier. They also cost about 1/5th or less than comparable mbls. OHM sound is more coherent through the midrange than mbl 111 due to the single wide range Walsh driver.

Dynaudios and Triangles can do the trick very well also when set up correctly.