To decide what Beethoven sonata to play, it will depend on whether you like early Beethoven or late, and what kind of piano you are going to be playing on, and the acoustics of the room. If the acoustics are "dry", for example, the arpeggios of the moonlight sonata might come across as too stolid. I have an 81-year-old solid walnut baby grand on which the beauty of the first movement of opus 28 -- in the book, just after the moonlight -- is apocalyptic, however far from flawless my performance of it may be.