What is the best sounding Mahler symphony cycle?

The Fisher recordings are great if you haven’t heard a top tier orchestra play Mahler. It’s more an “audiophile” recording than great performances. As for a recent recording there are so many excellent ones from Los Angeles, Philadelphia, New York, Chicago, Berlin, and Concertgebouw. 

@mayoradamwest , @schubert 
The Fisher/Mahler are certainly audiophile quality recordings, and maybe that's one of the reasons for my enthusiastic response to them. I do think Fisher has a good grasp of Mahler from what I've heard. But since there's no compilation of the cycle, I'm exploring the symphonies one at a time.
It's a joy hearing symphonic music recorded with great care using proper microphone placement.

I think it's Grammaphone who lists the Budapest as a world class orchestra, currently rated at number 9.

To add to other's comments, I agree that Haitink/Chicago is top-class Mahler.

I think we are spoiled for choice in Mahler.  The greatest Orchestras —in no particular order, the Berliner Philharmoniker (the fashionable way  to refer to that ensemble), Vienna Philharmonic, Bavarian Radio Symphony, Amsterdam Concertgebouw, Chicago Symphony)—have all recorded multiple Mahler cycles. The Cleveland, London Symphony, Philharmonia have all had significant Mahler recorded histories.  The New York Philharmonic cycles with Bernstein (I am more familiar with the sixties cycle) and the London Philharmonic live recordings with Tennstedt represent two cycles with excellent ensembles /Conductor combos with particular Mahler affinities. 
  As I alluded to in my first post, lately there has been an explosion of Mahler recordings, many with Orchestras that perhaps aren’t thought of conventionally as ready for prime time.  Witness Fisher brother #2 and his hardworking Dusseldorfers.  I haven’t heard many of these although the reviews are excellent.

Regarding Haitink/CSO, I live in Chicago and was present at some of the concerts from which the aforementioned recordings were made.  My favorite Haitink/CSO Mahler concert was the First, and for some reason I never acquired the recording that was issued, because I don’t think it could match the experience of that night.
  I was a bit disappointed with the recording of the Third, which as I foreshadowed above, dulled the memory of a fine evening in the Hall.  To me the sound of the recording is a bit dry in places, and not consistent with my aural memory of the evening.  Curiously I don’t feel that way about the Haitink/CSO Sixth, but otoh the Sixth doesn’t really play to Haitink’s strengths (his Amsterdam recording is relatively blah, but his Amsterdam cycle on BluRay is a sonic treat).

Regarding Fisher and Budapest, I heard them in concert here this year on tour.  Their Channel Classics recordings strike me as being faithful at capturing their sonority.  They have a lean, finely chiseled sound.  Their woodwinds have great character.  The brass is finely tuned.  The CSO   brass would undoubtedly blow them halfway to Milwaukee if they had a shootout, but the Budapesters aren’t trying to win a testosterone war.  The Orchestra that they remind me the most of is the Czech Philharmonic, but the Budapest has a bit more heft in the strings.