One CD of the Mahler Fifth is not enough. Finally, budget and plan your purchases. How to Choose Beginning CD collectors are often shocked to find out how much product is available in the classical realm. Even though some of these listings represent the same performance issued with different couplings, that's an enormous number of performances. And they are different.
Every performer finds something unique to say within the bounds of the printed score.
Acoustics of the hall or studio, sound of the piano, singer's personality, etc. etc. can also make a profound collective difference. You will hear the difference, and it will matter to you. Perhaps you already have a favorite soloist or conductor, someone you prefer over all others in certain repertory. Then your choice will be easy. For the rest of us, a little help is useful.