I started McCaffery years ago with the Ship books (which I very much liked) and some of the Talent books. But I have to agree that the Dinosaur Books were pretty much a mistake. But the Crystal Singer is quite good, didn't like the 2nd one as well, and consequently didn't read the third. I liked the Doona series, but couldn't get into the Acorna though I read several of them.
As to the Pern series, I've read them all, some multiple times. I finally got Tony to read All the Wyrs of Pern which answered some of his questions about what happened next. I'm very anxious to see how the newest one--by Todd is, but haven't read it yet.
One of the things that rather fascinated me was the way in which McCaffery (as well as Pratchett) has written a batch of "children's books" although hers don't seem to be identified as childrens in the same way. And although I think Dragonsinger, Dragonsong, and Dragon Drums immediately spring to mind, so does The Dolphins of Pern, and to some small degree parts of The Masterharper of Pern. If she has done anything similar to Maurice and the Educated Rodents, I don't know it--but the others certainly compare very well to the Tiffany series--or at least I think so. What do the rest of you think?