Strauss's chamber opera, preceded by a theatrical spoof as a first act, has had devoted -- even besotted -- admirers since it first appeared. There have been half a dozen notable recordings in the modern era, but I think only four are serious rivals for top place. Let me give the pluses and minuses of each as fairly as I can.

1954 Karajan (EMI) - The Karajan set hasn't been out of print for over fifty years, and its two biggest pluses are unarguable: a dream cast of hand-picked singers and the young Karajan's superb conducting. Schwarzkopf gives one of her greatest performances in the title role, a miracle of technique and characterization. All the other roles match hers in theatricalaity and freshness. Rita Streich amazes with her accuracy and briliance in the coloratura role of Zerbinetta. The weak link (this will become a familiar theme) is the tenor who must engage the voice-killing role of Bacchus. Rudolf Schock sounds tight and strained, but overall he's doing as good a job as all but the very best.
The minues are few, consisting mainly of the boxy, dry mono sound that remastering can't disguise. At least EMI has managed to remove some shirlliness from the high frequencies, and one can say that the final product is quite listenable.

1987 Levine (DG) - I am skipping ovver a Sixties recording under Kempe (EMI) that some critics rate very high. I much prefer James Levine, who made the first recording of Ariadne on CD. He leads members of the Vienna Phil. in a sweet-toned, deliberately paced reading that is quite sumptuous. His cast mirrors a very good night at either the Met or the Vienna State Opera. Tomova-Sintov gives her all dramatically as Ariadne, and despite some vocal strain, she triumphs in the role of the vulnerable stranded heroine. Even better is Kathleen Battle as the most coquettish and sweet-voiced of Zerbinettas. Levine had picked Gary Lakes as his Siegmund in Walkure, but the Texas heldentenor was never a star. Here he's quite good, however, as Bacchus, despite some tightness in the upper range.
There are no serious minuses. The unremastered digital sound tends to be a bit metallic and shrill in the upper ranges, but not seriously so.

1988 Masur (Philips) -- Coming so soon after Levine's set, Masur's is equally impressive overall, even if it's not the last word in theatricality. The conducting is solid Kapellmeister work without being brilliant, yet Masur has an ace in the hole with the recorded sound, which is airy, detailed, and delicious -- despite some residual shrillness in the upper voices, no rival comes close. His Leipzig Gewandhaus musicians play with refinement and delicacy, making up for Masur's occasional lack of dramatic thrust. The cast is dominated by the stellar Ariadne of Jesseye Norman, the only modern soprano to give Schwarzkopf a run for her money. As always, Norman doesn't bother to offer much in the way of character -- she lets her sumptous, effortless singing carry the day, and it does. Her Bacchus is the pleasant-voiced but hardly great Canadian heldentenor Paul Frey, who never had much of a recorded career. Edita Gruberova was an authoritative Zerbinetta on stage; I find her a bit edgy and too mature, however. Special mention should be made of the famous husband-and-wife team, Dietrich Fischer-Dieskau and Julia Varady, who are outstanding as the Music Master and Composer (Varady is surprisingly successful at bringing a sosprano voice to a role usual taken by mezzos).
The minuses are negligible. For me the pacing is a bit staid, and I wish Norman were more than a glorious voice. For all its virtues, the performance reaches its climax about halfway through and tends to run down toward the end, largely because of Frey's lack of authority and Masur's depleting vitality.

2001 Sinopoli (DG) - This set was released just after Sinopoli's premature death while conducting Aida in Berlin, and it's a fitting tribute to his vivid, imaginative way with Strauss. Acclaimed for his Salome with Cheryl Studer (DG), Sinopoli is jsut as good with Ariadne. His singers are the second 'dream cast' that this fortunate opera has received over the years. As a pair, the Ariadne and Bacchus have never been bettered. Deborah Voigt has a perfect Strauss voice, and Ben Heppner delivers a thrilling Bacchus that is far ahead of the competition for ease, sweetness, and musicality. Voigt can't match Schwarzkopf in dramatic authority, but the sheer sound that these two singers make is ravishing. The supporting cast is nearly flawless, and althoiugh I don't respond especially to Natalie Dessay's Zerbinetta, finding it more a technical feat than a lovable coquette, she is exemplary in the role.
In my view there are no minuses to this set. One can nitpick that certain singers aren't the very best in their roles, yet they all come close.

The final result, then, is that any lover of this unique opera should try to own two versions, the classic 1954 Karajan, particularly for Schwarzkopf's matchless contribution, and the 2001 Sinopoli, the closest modern equivalent to the Karajan. I can't narrow the competition down to just one winner, because some listeners won't be able to tolerate the boxy mono sound of the Karajan, while others may be set against Sinopoli on principle because he is too individual and willful. In any case, Ariadne has been amazingly well srved on CD. Few if any other Strauss operas have received four recordings of such high quality.