Most Sublime Beethoven Symphony

I'm no guru, but I'll chip in.
Not the whole symphony, but the second movement of the 5th symphony is my favourite (of those I have heard). I could listen to it forever. Don't much care for the "pompous" first movement though.
On the Beethoven subject but straying to piano concertos I recently purchased the "emperor" (I forget the number). Again the slow movement is sublime.
Also in Piano sonatas the Appasionata I think is my favourite so far, but I still haven't heard them all.
As for performers .. well I like Ashkenazy on Decca ... I gather he's a bit of a love him or hate him as far as Beethoven goes, but I think he plays with great feeling.

There are so many to choose from. I enjoy Harnoncourt's recording of the third and Furtwangler's Berlin recording of the ninth. I also enjoy all of Klemperer's recordings.

My recommendations are:

For a new perspective listen to John Elliot Gardiner. Great sound, new scores prepared from from Beethoven's manuscripts, wonderful playing and conducting, and a true "classical" sound, authentic to the period.

For simplay magical playing listen to any and all of the Fritz Reiner/Chicago Symphone recordings. The playing is astonishing in its tightness and rhythmic drive. Some of the symphonies are available as XRCD discs and sound as good as I've heard.

For historical perspective the recordings by Klemperor and Furtwangler are wonderful. I always loved hearing Karajan live but the recordings do not sound good to me.

as for the Emperor Concerto, you will be blown away by Horowitz and Reiner on RCA (yes Horowitz); simply a joy. And every piano player loves it and wishes they could play is so effortlessly. It is Horowitz in his prime, circa 1955.

For performances that are both vigorous and rigorous, you can always count on Solti/Chicago. The miking/mixing isn't always the greatest, though. Sometimes you have to listen around the bonehead engineers.

will

I have about 8 different recordings of the 6th Symphony
(including the one by Reiner). The one I like best is the one by Karl Boehm with the Berliners; the Karajan is too fast. On the other hand I don't like Boehm's 5th, but like
Karajan's/ And, Karajan's 1962 recording of the 9th is the
best I've heard. Caveat: I'm not a musicologist or guru; I just know what I like.

Also listen to the Pollini/Boehm 4th Piano Concerto.

The Triple Concerto is a truly wonderful piece of music. I have the recording by Anda/Fournier///Can't remember the rest, but if you're interested, can send you the LP info.