High value, giant killer speakers?

No longer in production but Mirage M1si and M3si are incredible speakers for the money. They come up on the used market occasionally for under $1500 or so (mine were $2300 new). I have a pair of M3si's and after attending two audio shows I can safely say they easily compete with many speakers that cost 5 figures. I just got a pair of Thiel CS 6 speakers and they certainly have their strengths but I would not call them better overall. One downside is that both of these speakers eat amps for breakfast. You need big solid state wattage with the ability to drive difficult loads.

I would also put in a second vote for the Golden Ear Triton Reference but I would go so far as to call it a giant slayer. To my ears in two different occasions the Tritons sounded as good or better than several speakers that cost 5 times as much. Unlike the Mirages or the Thiels these speakers are very easy to drive meaning that you have an infinite selection of amps - both tube and SS.

This is a great way to end up with a mediocre speaker. :(

We're fans of the old Acoustic electrostatic speakers.  The 2MH hybrid predated the Martin Logan Monolith by a couple of years, and at less than a third of the price.  Huge bang for the buck.  2+2's and 1+1s are also great examples.  Panels aren't for everyone, but in this particular area, Acoustat definitely delivered.  

Magnepan the whole line.  LRS is the new small offering $650. It is designed to work well with high end electronics but a quality receiver is an acceptiable starting point.  They are 4' tall and work well with quality fast subwoofers.

Used Verity speakers, if you can find them.

The OP said $10k, so I’m pushing the slider to the top and saying, try to get something from Verity at the $10k mark. This usually means a speaker pair that was maybe $20-25k when new.

Instructions were simple. Best universally recognized under $10k speaker.

The universally recognized bit is unspoken but when addressing someone’s desire to get the best they can and without information on their tastes and ear trained/innate skewing...then what we’ve got is the universal speaker, not my personal tastes or some other one sided predilection. 

Verity sort of flies under the radar but they are definitely among the best. The Europeans seem to note this, as they do far better in Europe than in north America, at least with respect to used items available.  Even with the higher premium that something like the Verity speakers would command, when available in Europe.

I like them because they are neutral in all the right ways, they are dynamic in all the right ways, and so on. No games, no colors, no new one trick wonders of the given audio moment or whatnot.