A really great sounding, classic DG recording is the Dvorak Cello Concerto with Pierre Fournier, George Szell and Berlin Philharmonic. The performance is superb and supplanted the Karajan / Rostropovich as my favorite recording of this piece. The tulip LP's are difficult to find in good condition, but the later reissue on DG's budget label is excellent-sounding too, and is easier to find in good condition.
Also in excellent sound with superb performance is the Beethoven Triple Concerto with Geza Anda, Wolfgang Schneiderhan, Pierre Fournier, Fricsay and Berlin Philharmonic. Same applies as above, don't be afraid of the budget LP reissue on DG Privilege. In fact, it sounds better than my tulip pressing. Go figure.
For admirers of the Berlin Philharmonic: NOT on DG, but a new recording of the Schumann symphonies with Simon Rattle and the Berlin Philharmonic - released on the Berlin Philharmonic's own label - is well worth downloading in high resolution. The sound is fantastic and the performances will make you re-think these symphonies. I bought the LP's also, but the digital beats them.