I second the recommendation of Carlos Kleiber's performance of the 5th and 7th - truly outstanding.
If you have an interest in exploring some "original instrument" performances of the symphonies, try Roger Norrignton on EMI - particularly his performances of the 2nd and 4th.
If you have an interest in exploring some "original instrument" performances of the symphonies, try Roger Norrignton on EMI - particularly his performances of the 2nd and 4th.