Mahler's 8th is a project I set for myself for later this year. At now I don't have enough confidence in my exposure to it to make a strong buying suggestion. It's a colossal work whose performance, imo, demands as much from the choristers and solo vocals, and their proper integration, as it does from the orchestra. If you put a baton to my head and said "choose!", I might pick
MTT/SFSO simply on production values or
Bertini for a strong finish and great sound. My sleeper pick might be Kubelik. Never wise to discount Lenny B. Let's wait for Kal's remarks.
Without meaning to go all teach-a-man-to-fish on you, the two links to review pages in the opening post are helpful to browse and they make it easy to get at multiple reviews of this symphony. A glance finds positive noises made for
Solti ('apocalyptic'),
Rattle ('choral work beyond reproach'), &
MTThomas ('especially fine'); I've not heard the Rattle. Ask again in 6 months.
Arkiv shows 74 Eighths, all mentioned above are recommended w/ good commentary. Tennstedt & Boulez get solid notice too.
No need for last question boundaries - please.
Your enthusiasm is infectious and very much hope you share your choice(s) and listening notes!