I just enrolled in Eric Wagner's Maybe Logic Academy course of Schroedinger's Cat, and I noticed that Eric's course outline asks members of the class to listen to Beethoven's piano sonata, Opus 106, the "Hammerklavier" at least once a week. RAW wrote a lot about Beethoven, and I've noticed that he seemed to be particularly fond of the symphonies and of the Hammerklavier.
I can't point to a free source for the symphonies, but there are credible live, free recordings of the Hammerklavier online, including one by Finnish pianist Paavali Jumppanen at the wonderful music library of chamber music performances at the Isabella Gardner Museum in Boston; the link to download the recording is here. (One oddity of this particular file is that although the Web site identifies the performer as Jumpannen, the tag on the file identifies the pianist as Jeremy Denk. I asked Gardner spokesman Michael Busack about this, and he replied, "This is tricky as they have both played the Hammerklavier here at the museum in 2008, but Paavali’s recording is the one that we featured on the website.")
Another recording is available from my favorite music blog, Boom's Dungeon. He recommends a live recording by Martina Filjak, writing, "Her Hammerklavier is bracing and propulsive, yet there is always a singing quality to her melodic lines, and the tone never becomes brittle or harsh even in fortissimos. With its flowing tempo the Adagio emerges as a wistful elegy instead of a funereal dirge, and the music only gains from the underlying subtle sense of urgency." For the URL to download the recording, see Boom's entry in the comments.