I suppose that if you liked Terry Gilliam's excellent film, you'll most likely enjoy its soundtrack...it has generous snippets of film dialogue, and much of the score is intact.
But since we're concerned with our man Harry here, I can recommend this album on the strength of "How About You", which sounds like it would have fit nicely on ...That's the Way It Is or Sandman. If you can find this at less that retail, then snap it up, it's worth having for a fine Nilsson song that to my knowledge doesn't appear anywhere else.