Many listers here rightly recommend the Richter and the Michelangeli.
If you are only going to have one version, I think the safest bet is the
Zimmerman.  Michelangeli sometimes is a little free with the printed score,
albeit beautifully so.  They do tend to float rather freely at times.
Richter is live and has all the pluses and minuses of a live recording.

I also have enjoyed the Gieseking Preludes from the complete set of Debussy
piano music (EMI).  For many this could be a first recommendation, but it
is mono and that may be a turn-off.  But for people who like that sort of
thing, it is just the sort of thing those people will like.

Ray Osnato