I read all the way through *all* of the Dr. Dolittle series 4 or 5 times. I think my favorite of the bunch was Dr. Dolittle and the Green Canary. But I also liked Willows ... In my late 20s, had a minor obsession about collecting oboes of various types (two oboes - one for safety, an english horn, an oboe d'amore), and when I got a new one, I'd look at my housemate and go "putt, putt, putt, putt", while shifting an imaginary gear-shift who definitely understood the reference
And of course there were other Oz books. Can't remember all the titles now, there was one about Ozma, and another centered around Tick-Tock.
But I also liked both Winnie the Pooh and House at Pooh Corner, and when I was much younger, the Dr. Seuss books.