My Go To performance of the symphony is still Bruno Walter's on an old Odyssey. But, yeah, I gotta try the Giulini.
Found an excellent classical recording on Qobuz
Gustav Mahler's Symphony #1, "Titan." On Harmonia Mundi. The orchestra is Les Siecles. Francois Xavier-Roth conducts. Recording is spacious and balanced. Wonderful orchestral string tone. For those not familiar with the work, it's quite accessible. It's filled with tunes and a sense of adventure. It takes you to a planet earth a long time ago. Performance might be a bit leisurely but the work is played with great affection. I'm streaming it as I write this. Lovin' it.