Best imaging stand mounted speakers?

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).

This would be a good choice:
http://cgi.audiogon.com/cgi-bin/cl.pl?spkrmoni&1044727976&2&3&4&

JM Reynaud Trentes. I just sold my Nautilus 805 (which image extremely well). The little-known Trentes are super.
check out the Jean Marie Reynaud website for some gushing reviews...

Seandtaylor99, thanks for your observations. No offense taken concerning your recommendations about placement. As far as price is concerned I'd like to stay in the range of $2500 new or about $1200 used. The speakers would be set up in nearfield listening conditions and driven by a Pass Aleph 30 for starters. I would change the amp if necessary.I mostly listen to show music, classical, opera, female pop (i. e.- Eva Cassidy, Ella), folk, soft rock...no heavy metal. Thanks to all for suggestions offered so far.

Thanks Beemerrider. I'd have thought in that price range you'd have to consider the AudioPhysic Steps. Not that I have heard them, but I have read glowing testimony to their imaging ability, and they're from the same company as the Virgo. Another speaker that I haven't heard but would be the absolute top of my demo list is the Harbeth Compact 7, which is Harbeths latest incarnation of a BBC monitor design. Have fun shopping for toys ... I think it's a good buyers market in that price range.