The best speaker you ever heard?

Cts, i've heard the older model JRDG & Boulder amps (not Ayre), and previously owned a Boulder 1060. All these companies have an essential house sound, and their latest products build on that and are more refined. Boulder is very quiet, smooth, neutral & has a lot of power/control. I enjoyed my time with Boulder. Paired with an modded Ayon tube preamp ,the 1060 was a perfect match with my old Marten Coltrane Alto's.
I've heard various Rowland products before, including the 625 stereo amp & Corus pre, and they sound very resoloving, quiet, liquid & airy. But they always sound a bit forward and mechanical to my ears compared to Vitus or Soulution. Rowland is a big fan of SMPS psu's which i've never been a fan of. Granted they are military grade & he has been developing them for some time, but i'll pass. Also the Corus preamp is chock full of op amps.

I have heard many of the greatest speakers from the early 50's to the present. Different people have different sonic priorities. Without going into specific attributes (which I could easily do) my bottom line is measured by the degree of emotional connectedness I feel with the true beauty the composer intends (e.g. Vivaldi's Gloria, Mozart's Regina Coeli, Beethoven's 9th Symphony, Amanda McBroom's version of The Rose, Leonard Cohen's Hallelujah, etc.). The Muraudio speakers out of Canada convince my brain that it is hearing reality like no other speaker I have ever listened to and commands my brain to pay close attention. These speakers also command my brain to forget analyzing and to just experience the thrill of great music. I'd be curious to hear the reaction of others on this forum after experiencing this game-changing product.

Never heard the Muraudio's. How old are they? Were they sold in the US?

The Muraudio electrostatic array speakers are a current product which I believe were developed within the last couple of years. They're made in Canada and sold in the US, and have been on display at recent audio shows including AXPONA 2015. Their sound quality is very unique and I found them to be quite impressive and captivating. Unfortunately for most of us they sell for $63,000 (passive version) and are reviewed in The Absolute Sound issue 258, December 2015. The reviewer concluded that he would buy them if he could afford them. http://www.muraudio.com

From what I heard at Axpona this year, the Muraudio speakers would be on my very short list if I had the funds and a room of the proper size for them. They were outstanding and a must hear if you are shopping in that kind of price range.