Best imaging stand mounted speakers?

Biro L/1's, which I use on Osiris speaker stands. So far as I know, Van Alstine (www.avahifi.com) is the only dealer who sells the Biro, so they're pretty much a mail order product anyway. (The Biro Technology site is www.birotechnology.com.) They're a two-way with 17 cm woofer. The sound around the crossover point (3000 Hz) is as seamless anything I've heard--maybe that contributes to the good imaging. Of course, the listening room has a big effect on imaging quality. With the right room and speaker placement, there are quite a few loudspeakers that produce nice imaging.

Piega C-2 Ltd. Not cheap but no equal.

Second the Spendors...few speakers of this size do the "space thing" so right...a little colored...limited bass...but the midrange accuracy is really unrivaled...top Brit speakers such as Proac,Castle,and even the new Quad L series have this in common...unlike alot of monitors...they dont sound thin and bright...for a leaner,analytical,"transparent" type of sound...the out of box imaging on the Triangle Titus and Paradigm 20...both in the $5-600usd range...these do require warmer equipment to sound their best...and if you have tubes...look no further...the revel M20 at roughly 3x the cost is a good option as well...good luck...

Hi Fi,

How much do the Piega's sell for?

You gave no price range ... if cost is a concern then a good pair of used Spica Tc-60s might be just the ticket. About $450 used inc stands.
I expect that you're aware that to image well the speakers must be quite well out into the room, at least 2 feet from the rear wall (that goes for all speakers I have ever heard). Please don't think that I'm trying to patronise you, but I see so many people buy expensive speakers that image really well and then throw all of the money away by pushing them up against the rear wall (usually due to WAF concerns).