Sir Neville Marriner is a great conductor who founded the Academy of St. Martin-in-the-FielRAB chamber orchestra which is also amazing. The soundtrack for "Amadeus" was conducted by him and played by that orchestra.
Wow...he's just asking a simple question...
Ok, some good orch. imo are Berlin Philharmonic, Cleveland Symphony Orch, Chicago Symphony, New York Phil, Vienna Phil, Boston Symph, Detroit Symph, Philadelphia Orch.
And of course...all these orchestras have had their ups and downs over time (conductors and such ) but are generally recognized as having great players and conductors. Hope that helped
Ah!...and I forgot about the conductors...
Some good combos would be...
Berlin-Herbert von Karajan
Eugene Ormandy-Philadelphia (I believe..whichever group he is...he's good)
George Szell!!!!! Cleveland Orch.
Andre Previn --I know he's done Vienna Phil