I just bought John Eliot Gardiner's 1994 DGG recording with the Orchestre Revolutinnaire et Romantique, a period instrument ensemble, a 5-CD full symphony cycle at just a little over $60, not a bad value.
My existing Beethoven recordings are all scattered, some Karajan, some Klemperer but the worst is that they are mainly on vinyl discs which I hardly play nowadays and need to be specially connected up for the occasion. Those that I have in CDs are in compilations which are not particularly good.
I bought the Gardiner set purely based on reviews:
"It leaves every other period instrument Beethoven set for dead" said Classic CD.
BBC Music Magazine carried this comment "I felt as if I were hearing [the symphonies] for the first time".
I only have the opportunity to review the 5th and the 6th in the car. I felt a veil had been lifted from some of the older recordings I was more used to. The energy and spontaneity seemed to come through more directly. The period instruments made their presence strongly felt. Generally a well balanced recording for the 5th.
The 6th found the interplay between the wind and the strings fleeting easily from one to the other with amazing lightness, which is just right for this piece.