I know Horowitz! He owns the bakery at the corner of my street, and makes the best bread in town. I didn't know he plays the piano, though... I'll ask him when I get my muffins tomorrow morning.
Well, jokes aside, Pollini recording of Chopin Polonaises is pretty famous and I consider it the best along with that of Rubinstein.
He's, of course, technically impeccable (his Boulez 2nd sonata or Stravinski Petroushka are amazing), but his style can be considered a bit cold (compared to Argerich, for example). Surprisingly, I bought his CD of Beethoven last sonatas expecting to be blown out with the Hammerklavier but not with the others, and I found his op. 111 quite moving... Although I haven't found my definitive version of op. 111 (I can't get the perfect performer for it yet), Pollini is one of the tops on my list for that sonata.