Since this thread is Best Recordings ever, and the Tchaikovsky symphonies came up...skip Svetlanov (horrible soviet era sound) and Mravinsky only does 4, 5, 6. Recently I acquired all six symphonies, Manfred, 1812 and more with Ricardo Muti and the Philharmonia & Philadelphia. I've collected several dozen sets of 4, 5, & 6 and quite a few complete cycles. There is none, not one, that is better than this set. The playing, conducting, recording are all beyond reproach. Exciting as it can be. The finale of the 3rd is exhilirating, as is the 5th. The 6th is an emotionally draining experience, and the Manfred is after all these years still the best ever done. The most amazing thing is the price from Berkshire Record Outlet: $20. But wait, there's more...you also get John Lanchbery's recordings of the three ballets. They're good, and quite enjoyable, but the addition of a piece in Nutcracker, and the omission of the one most recognizable scene in Swan Lake drives me nuts. But get the set for the symphonies: you'll never regret it.
I've enjoyed the old Markevitch recordings so much. For some reason I just skipped the Muti's: but there's no question. Muti is a master Tchaikovskian. Far better than Abaddo, Jarvi, Temirkanov, Karajan, Rostropovich, Bernstein, Pletnev, Dorati. Nice as their sets are, Muti's better.