What is the best phono preamp you have heard?

I think so far -- IMHO -- it has to be a toss up between the Boulder 2008, Precision Fidelity C7/A Revised, and Counterpoint SA-5000.

The Nagra VPS.

I have yet to hear a best phono stage...I own/owned a few good ones: the Aesthetix-Eclipse and Signature both with 2 power supplies and NOS tubes, Lamm lp2 deluxe with Western Electric 417a tubes, Allnic, Manley Steelhead, VAC Renaissance, etc...because there is no single best. Obviously, system dependence plays a major role, but I am not sure one unit can be a "best".

You have to decide on what you are willing to spend, what features are important to you and compromises you are willing to live with and live with them.

If I could plug in one unit that simply is the best, my wish list would include-ultra low noise, huge variable gain, infinitely adjustable settings from a remote, neutral to the extreme, plenty of air and bloom, very low
distortion, and most importantly the ability to play more often than not music that makes me feel like I am at a live performance.

I have not heard one like this yet

The AMR phono stage has most of the features you desire, perhaps even the last one.

I haven't had opportunity to sample many high end units, the seduction was great IMO, and the bottlehead Eros is now the best I've personally heard!!! After 8 months, I'm still loving it!!!