I've been listening to some opera recordings by the Czech conductor Raphael Kubelik, a very underrated conductor who somehow managed to rack up a huge catalogue of recordings on a major record label (including complete Mahler and Dvořák symphony cycles) without ever becoming particularly famous. He didn't get a lot of chances to record opera -- most of the big opera recording projects were given to bigger-name conductors like Karajan -- but when he did, he always turned in excellent work, and these three recordings of three very different operas would be somewhere near my first choices for these pieces:
1. Verdi, Rigoletto - A recording with a rather strange concept behind it: take the orchestra and chorus of La Scala Milan, and an all-Italian supporting cast (Carlo Bergonzi, Renata Scotto, Fiorenza Cossotto) but cast the German baritone Dietrich Fischer-Dieskau in the title role. For some weird reason, it works. Fischer-Dieskau's voice is exactly wrong for the part of Rigoletto -- it's supposed to be a big, full, Italianate baritone voice, whereas Fischer-Dieskau's voice is high and light -- but he puts so much conviction and real passion into his singing that it turns out to be one of the better versions of that part on record; Conrad L. Osborne, who didn't care for F-D's other attempts at Italian opera, was totally won over by this one. The young Scotto is a fine Gilda, Bergonzi is at his best as the Duke, and Kubelik's conducting is some of the best Verdi conducting on record. Definitely the Rigoletto to get if you're getting just one, and a very good introduction to Verdi.
2. Debussy: Pelléas et Mélisande - This is a live recording from two concert performances in Munich in 1971. The stereo sound is very good and the audience isn't too intrusive (there are a few stray coughs, but applause has been edited out). You wouldn't expect a German orchestra with a Czech conductor to produce a great performance of an early 20th-century French work, but it's actually quite fantastic -- instead of making Debussy sound cute and "impressionistic" as so many conductors do, Kubelik really has his orchestra dig in and bring out all the menace and brooding threats of violence in the score. (The opera is about repressed passions and meanings that are just beneath the surface, and the orchestral accompaniment -- which is really the main melodic material, because the singers mostly communicate in recitative -- constantly sounds like it's just about to burst forth in anger, but never quite does, or at least almost never.) The cast is very good, though the French pronunciation is variable; the highlight is Helen Donath, who is simply one of the great opera singers of her generation -- the kind of "light" soprano who could actually project more powerfully than many a bigger-voiced singer.
3. Wagner, Parsifal -- I must be nuts or something, because while I'm not that big of a Wagner fan, I do love the music of Parsifal, his last opera and the one that is generally considered to be the least accessible by non-Wagnerians. The libretto is insane hokum, with Wagner's patented weird mixture of the worst aspects of Paganism and Christianity. The opera moves at a slow pace even for Wagner, with endless expository monologues and scenes of chorus people standing around doing nothing. But the music has a hypnotic quality to it; the melodies are so strange (Wagner pushed the limits of traditional tonality and rhythm in this, his last opera, and sort of paved the way for the atonalists who would follow him) that they make you want to follow them and see what Wagner is going to do with them, how he will build the scene musically; and before you know it another half-hour has gone by, and you realize that, long as the opera is, there's not a lot in it that's really boring or redundant -- it's long and slow because that's what the material demands, but it's long and slow in a fascinating and even gripping way. This Kubelik recording was another studio recording that the major labels wouldn't release (Karajan had a competing version coming out, and that probably blocked Deutsche Grammophon from releasing it). It was finally released a couple of years ago, and it becma pretty much the first choice among studio Parsifal recordings; Kubelik's work is excellent and his cast -- the American heldentenor James King, the wonderful Australian mezzo Yvonne Minton, and the best German bass of his era, Kurt Moll -- is excellent.