Everyone should own the Complete Preludes and Etudes, published by Dover. They publish two other volumes, Complete Sonatas and miscellaneous pieces, that comprise his complete piano music... I think.
Many of the preludes and shorter pieces are quite accessible; get the books and read through some of them, you're sure to find some pieces you love.
I spent the better part of today with the G major and a minor Preludes from op.11, #'s 2 and 3. Should have been practicing Mozart, but I got around to that evantually...