Highest Quality Recording of Favorite Piece

Hey, I'm a very small enthusiast for classical music. I listen to youtube mixes on youtube. I'm always open to recommendations, so drop them down below, but I'm interested in one piece of music. I must have listened a few dozen different recordings several hundred times over the years. Leonard Bernstein's recording from 1988 is my favorite version of Requiem, but what is the absolute highest quality recording I could purchase. I'm aware that my headphones will limit my appreciation, but I have a decent set of wired headphones. What's the best and most full version?