What is the best sounding Mahler symphony cycle?

Why stick to one conductor and one orchestra? You can compile your own favorite cycle.
Here’s mine:
#1: Bruno Walter / Columbia Symphony (columbia USA)
#2: Otto Klemperer / Philharmonia Orchestra (emi/columbia UK)
#3: Zubin Mehta / LAPO (decca)
#4: Georg Szell / Cleveland Orchestra (columbia UK)
#5: John Barbirolli / New Philharmonia Orchestra (hmv)
#6: Georg Solti / Chicago Symphony (decca)
#7: Leonard Bernstein / NYPO (DGG)
#8: Georg Solti / Chicago Symphony (decca)
#9: Bruno Walter / Columbia Symphony (columbia USA)

This is almost exclusively based on the original vinyl issues (except the Bernstein 7th), but I’m sure these performances are all available on cd or SACD. Don’t know about the quality of the digital transfers, but the sound quality on vinyl is mostly excellent (exceptional in the case of the Mehta 3rd).

My choices have to do with vinyl being my primary source, but I guess they date me as well 😕

On original vinyl the Mehta #3 has no rivals sonically, although as a performance the Bernstein (both the CBS and DGG recordings) may be superior.

I forgot to mention Das Lied von der Erde, but here Klemperer on HMV Angel has my preference (yep, another oldie). As for #10 (Cooke version), I like the Rattle on EMI, but I'll admit that I haven't heard any other performances.