Well, I must reiterate Bach's Cello suites by Rostropovich -- IMO some of the best (if not the best) music ever written, and I think that Rostropovich's performance is the best I have ever heard. I also love Casals' and Fournier's versions.
Starker's recording of Kodaly's sonata for solo cello op8, also duo for violin and cello with Gringold.
Britten's cello suites are also very good.
Debussy's cello sonata is gorgeous.
Shostakovich's First cello concerto, also by Rostropovich, the US premiere recording with Ormandy is phatty.
I love Judith Ingolfsson's debut recording. I heard her play the Brahams sonata's in concert and she was fantastic, I picked up her recording and was blown away. I like her recording of Bach's 3rd violin sonata better than Heifetz's (!), and I also really like the Bloch and Rorem pieces. It is a good recording. Check it out. Anyway, those are some of my favorites...there are many more of course, but I will hold back.
edit: on the Britten suites, I own the Rostropovich (on London vinyl) and have heard the Hugh. Surprisingly, I like the Hugh better. He is more abrasive in his interpretation, which I think is something that these suites need. Rostropovich is almost trying to make them pretty or romantic, which IMO does not work at all. Still an excellent recording, but there is just something wrong in it...