My favourite prelude -- and, if Moiseiwitsch is to be believed, Rachmaninoff's (it reminded him of home, or so the account goes.)
A lovely performance that moves between intimacy and deep grandeur. The middle section, beginning at 01:39, is very moving. Played by Boris Berezovsky live in Mainz in 2006.
The use of Neapolitan and modal harmonies, as well as suspensions (e.g., 4-3s that never resolve down), is pretty masterful.