Thanks, Cpdunn99, for your recommendations.
Here are two more recommendations for organ CDs that I've found outstanding.
1. Michael Murray, Bach, The Great Organ at Methuen (Mass.), Telarc CD-80049. In my opinion this is one of the greatest organs in the USA, and it has an unusual history. Built by the Bavarian firm of Walcker in 1857-63 for the Boston Music Hall, it was the first concert organ in the country. In 1884 it was dismantled to give stage space for the new Boston Symphony Orchestra. In 1897 it was purchased by a wealthy gent who commissioned a lavish new music hall in Methuen Mass. for it, where it was installed and rededicated in 1909. It must be one of the very few organs in the world that enjoys its own music hall built especially to house it. It was revised and rebuilt by the famous G. Donald Harrison of Aeolian-Skinner in 1947. Today it has four manuals, 84 stops, 115 ranks, and more than 6,000 pipes (including two 32-foot pedal pipes).
The description of the tonal qualities of this organ in the CD notes (uncredited, but I suspect by Murray) is so apt, so right-on-target that I'd like to quote it: "Neither wholly romantic nor wholly classic, the Methuen organ partakes of both styles of instrument and is suited to both styles of music. Its beauties include a unique mellowness that comes only to well-built flue pipes and only after decades of seasoning, and a miraculous blending of 8' foundations, whose harmonics interweave like the colors of a tapestry. The tutti is overwhelming, not abrasive. The mixtures are bright, not shrill. The foundations are full-bodied but remain, in even the most complex polyphony, clear. Accordingly, the Methuen organ is renowned as one of the world's artistic treasures." Indeed, it's a rare beauty.
Why this magnificent organ isn't better known and hasn't been more frequently recorded is a mystery to me. I used to have an old mono Columbia LP of Biggs playing a recital on it. If there are other presently available recordings of it, I'd like to know about them.
2. Michael Murray, Bach, The Organs at First Congregational Church, Los Angeles, Telarc CD-80088. This Skinner-Schlicker instrument is a very large organ in a very large church. Actually it is two organs at opposite ends of the nave, with twin consoles, four manuals, 214 ranks, "including several of 32-foot pitch" (I don't have the specification). Again, a superb big organ. This recital includes the ubiquitous Toccata and Fugue in D Minor BWV 565, in a performance as stirring and satisfying as any I've heard (and anyone who's an organ buff has heard a great many!).
To my ears both these Michael Murray Telarc CDs have it all: a master organist playing major Bach works on two magnificent instruments, both with exemplary sound: full, rich, clear, and vivid, with excellent, natural bass. If you relish organs and organ music, it doesn't get much better than this. Together with the Murray "The Young Bach" CD on Telarc described in one of the posts above, these are three of my "desert island" organ CDs.